Indicator unit for an electronically controlled camera

ABSTRACT

An indicator unit for an electronically controlled camera that is able to effectively indicate required information for operating the camera. Such information includes, for example, the frame number of the film in the camera, the focal length of the camera lens, the picture-taking mode, the status of the battery in the camera, and the status of the loading of the film. A display panel constructed according to the invention can display such information within a limited indication space while providing a legible display format. More specifically, the present invention provides an indicator unit for an electronically controlled camera that includes an indicator that is adapted to store a first piece of updatable information in a first memory and another piece of updatable information in a further memory. Display priority is given to the first piece of information stored in the first memory. In response to the further piece of information, the indication status of the indicator is switched from indicating the first piece of information to indicating the other piece of information in accordance with the operation of the indication control device when the switch that is responsive to the other piece of information is operated when the first piece of information being displayed on the indicator.

BACKGROUND OF THE DISCLOSURE

1. Field of the Invention

The present invention relates to an indicator unit for an electronicallycontrolled camera.

2. Discussion of Background Information

In a camera equipped with a zoom lens, it is necessary to know theF-number of the zoom lens so that a proper exposure can be calculated.In addition, if the camera has a power zoom lens, the focal lengthsetting must be known so that the camera can control the zoomingoperation.

A conventional solution to the above problems has been to provide thezoom lens with a code plate located on a cam ring for driving the zoomlens for integral rotation therewith. In such an arrangement, brushesare provided in slidable contact with the code plate for generating aposition code that corresponds to the focal length of the lens independence upon the zoom code detected as a result of a conductive statebetween a ground brush that is normally in contact with the conductivepattern of the code plate and code brushes that come into contact withthe code plate during switching between conductive areas andnon-conductive areas of the code plate as the cam ring is rotated.

Each code brush generates a 1-bit signal that depends on the conductiveand non-conductive state of the code plate so that when several suchbrushes are employed, a multi-bit zoom code signal is produced. However,since the brushes and the code plate form a mechanical configuration,the code brushes can become separated from the code plate due toexternal causes, such as vibrations. In such a case, the resultingposition code that is calculated from the detected zoom code will notcorrespond to the actual lens position.

In addition, in determining the position code of the lens (i.e., thefocal length of the lens), the exposure control is likely to beimproperly set if the position code is not accurately stepped. Forexample, in a camera having a lens with a range of approximately 35 mmto 60 mm, the camera should preferably have about fifteen position codesto ensure that the exposure is properly calculated.

In a conventional camera, one zoom code corresponds to one positioncode. That is, an absolute code system is used in which each step of thezoom code has a unique value that is specific to that step and,therefore, is specific to a particular position of the zoom lens.

However, a problem associated with such an arrangement is that if thezoom code is set as an absolute code over the entire range of the zoomlens; the number of brushes that are used in association with the codeplate must be increased, resulting in a more complicated code platestructure.

For instance, if information in fifteen steps is to be detected, atleast four-bits of information are necessary for the generation of thezoom code. Thus, five brushes would be required, which includes onebrush for ground, to cooperate with the code plate. While it isdesirable to minimize the number of brushes that are required, so as toproduce a more compact camera, it is not practical to reduce the numberof steps of the position code.

Some electronically controlled camera include macro and normalphotographing functions which are switchable between a macro mode and anormal mode by a manual switch operation. In either mode, photographingis accomplished by autofocus in accordance with distance measuringinformation. A particular camera of this type is one in which the normalmode is constituted by a zoom mode and the camera is switchable betweenthe zoom mode and the macro mode, whereby the lens moves to and stops ata macro position when the macro mode is selected by means of the manualswitch and whereby the zoom lens moves to and stops within the zoomrange when the zoom mode is selected by means of the manual switch. Whenthe lens is in the zoom mode, operation of a wide switch or a teleswitch moves the zoom lens accordingly toward the wide portion of thezoom range or toward the tele portion of the zoom range, respectively.

The distance between the subject to be photographed and the camera, aswell as the subject light intensity, are measured when the zoom lens isset to a desired position and the shutter button is operated. Based uponthe result of the distance measurement, autofocus is effected in boththe macro mode and the zoom mode. Positioning is also done in dependenceupon the result of the light measurement.

In conventional electronically controlled cameras, if the subject isfound to lie within a range where focusing is impossible while in themacro mode, which is set by the manual switch thereby placing the zoomlens in the macro position, photographing can only be effected bymanually switching from the macro mode to the zoom mode. Thisrequirement, of course, creates a considerable inconvenience since aquick response is virtually impossible to achieve which can be necessaryto obtain the photograph which had been composed.

Applicants have recognized, therefore, that when the distancemeasurement is made when the lens is placed in the macro position byoperation of the manual switch, it would be desirable to automaticallyeffect switching from the macro mode to the zoom mode so that a subjectwhich cannot be photographed in the macro mode can be automaticallyphotographed in the zoom mode.

A problem encountered with such automatic switching, however, it that ifthe lens is shifted from a macro position to a normal position (zoomposition, e.g.), a desired photograph which had been composed in themacro mode cannot be obtained due to the parallax which exists betweenthe lens nd the viewfinder of the camera.

Another problem encountered with automatic cameras which are designed toperform autofocus photographing in either a macro mode or a zoom mode isthe possibility of not being able to accomplish photographing in eithermode due to subject distance measurement errors.

For example, assume that autofocus is designed to be performed in thezoom mode for a subject distance range of 0.9 meters to infinity (i.e.,0.9 m-∞). and in the macro mode for a subject distance range of 0.5m-0.9 m. Further, assume that the lens is set to the zoom position bymeans of the manual switch and that the distance measurement made by thecamera is 0.89 m for an object positioned at that distance. In such acase, the object distance is outside of the aforementioned focusingrange, so that a photograph cannot be obtained. In this situation,conventional cameras provide the photographer with a warning indicationthat a properly focused photograph cannot be obtained, instructing thephotographer to switch to the macro mode, or a release lock is operatedto prevent release of the shutter, even if the shutter button isoperated.

In response the photographer switches the camera to the macro mode bymeans of the manual switch. However, for the object positioned at thesame distance of 0.89 m, it is conceivable that the distance measurementmade by the camera can erroneously result in a value of 0.91 m. In thiscase, the photographer is warned that a properly focused photographcannot be made, or is prevented from releasing the shutter due to arelease lock operation, even in the macro mode.

This predicament is, of course, not desirable and is particularlyserious when the automatic camera is provided with a release lockcapability which renders impossible the taking of photographs within acertain subject distance range.

Another problem relates to cameras having a built-in strobe unit. Arecent trend is to provide a camera with a so-called auto strobecapability in which the camera judges whether to cause the strobe toflash automatically when an exposure value is below a preset level.

Such auto strobe camera are typically designed to illuminate a red lampindicator during the charging operation so that the user is warned towait until the charging is finished, or merely to warn the user that thecharging is not yet done and that the strobe is not ready when theshutter button is depressed.

An ideal arrangement would be to provide an auto strobe camera in whichthe photographer is allowed to shoot pictures without having to payattention to the charging of the strobe. In practice, a red lampindicator is either kept lit during the charging cycle or there is nosuch indication regardless of whether the photographer actually intendsto take a picture. That is, the problem has been such that the red lampindicator is illuminated to inform the photographer to wait forshooting, even when the photographer has no intention in pressing theshutter button for shooting, or that there is no indication of whenshooting is ready, although the photographer is waiting for the strobeto become ready.

Still another problem with prior electronically controlled cameraconcerns the liquid crystal display which indicates the differentoperating states of the camera. Such an indicator provides informationon the frame number of the film loaded in the camera, the focal lengthof the zoom lens, the picture taking mode of the camera, the status ofthe battery in the camera, and the status of the film loading operation,for example.

However, only a limited amount of space is available on the camera bodyfor such an indicator. If one attempts to provide a display panel thatcan display all of the desired information at one time, each indicatoron the display panel would tend to be so small as to be illegible. Thus,some cameras do not display all of the information, and merely displaythe information that the camera manufacturer considers to be the mostimportant to the average photographer. However, this practice deprivessome photographers who prefer to have all necessary informationavailable to them prior to taking a photograph.

Some electronically controlled cameras are equipped with a back coverclosing detector switch located on the back cover of the camera whichdetects the closing of the back cover after the cover is opened and filmis loaded in the camera. In response to the detection of the closing ofthe back cover, the main CPU of the camera drives the film advance motorto effect the "blank-shot" advance of a certain number of film frames.

Problems exist with back cover closing switches, particularly withregard to manufacturing difficulties and operational unreliability.Applicants have determined that it is preferable to use a softwaresubstitute for minimizing the number of parts such as switches that arerequired for film travel for enabling an improved assembling efficiency,while also making the operation of the blank-shot film advance morereliable.

SUMMARY OF THE INVENTION

In view of that state of the prior art as discussed above, it is aparticular object of the present invention to provide an indicator unitfor an electronically controlled camera that is able to effectivelyindicate in a limited indication space required information for taking aphotograph. Such information includes, but is not limited to, the framemember of the film in the camera, the focal length of the camera, thepicture taking mode, the status of the battery in the camera, and thestatus of the loading of the film. A display panel constructed accordingto the present invention can effectively display the requiredinformation within a limited indication space while providing a legibledisplay format.

In order to achieve the foregoing object, the present invention providesan indicator unit for an electronically controlled camera that includesan indicator means that is adapted to store a first piece of updatableinformation in a first memory means and another piece of updatableinformation in a second memory means. A means for controlling anindicator gives display priority to the first piece of informationstored in the first memory means. A means for changing indication statusof the indicator means from indicating the first piece of information toindicating the other piece of information when a switch means relatingto the other piece of information is operated with the first piece ofinformation being displayed on the indicator.

For instance, assume the frame number of the film in the camera is givenpriority for indication purposes on the display as the first piece ofupdatable information which is stored in the first memory means, asshown in FIG. 1C. The indication switching means operates to selectivelyswitch the indication on the display to show the other piece ofupdatable information, such as the focal length of the zoom lens.

It is an object of the present invention to provide an indicator unitfor an electronically controlled camera, including: a first memory forstoring a first piece of updatable information; a further memory forstoring a further piece of updatable information; means for providing anindication of information corresponding to either the first piece ofinformation or information corresponding to the further piece ofinformation; means for assigning a priority to providing an indicationof information corresponding to the first piece of information by themeans for providing an indication; at least one switch being actuatableto update the further piece of information in the further memory; andmeans for changing the indication provided by the means for providing anindication in response to actuation of the switch, from the first pieceof information to the further piece of information.

In accordance with a particular aspect of the present invention, thefirst piece of updatable information is the number of exposed filmframes which have been advanced by the camera.

In accordance with an additional aspect of the present invention, thefurther piece of information is the focal length of a movable lens ofthe camera.

In accordance with a still further aspect of the invention, the at leastone switch which is actuatable to update the further piece ofinformation includes a tele switch and a wide switch for enablingmovement of a movable lens of the camera.

A still further aspect of the invention includes the camera having atele switch and a wide switch for moving a zoom lens, and wherein themeans for changing the indication provided by the means for providing anindication operates in response to actuation of the tele switch or thewide switch.

In a still further aspect of the invention, the at least one switchwhich is actuatable to update the further piece of information includesa light measuring switch.

In a still further aspect of the invention, the means for providing anindication of information corresponding to either the first piece ofinformation or information corresponding to the further piece ofinformation includes a visual display.

In a still further aspect of the invention, the visual display includesrespective display areas for indicating film-related information,picture-taking mode, and a battery status indicator.

In a still further aspect of the invention, the display area forfilm-related information includes a display area for film-loadingrequest information that the presence of film is sensed and is ready tobe advanced to a predetermined position.

Still further, the display area for film-related information includes afilm-loading display area that film is being advanced to a predeterminedposition.

Additionally according to the present invention, the display area forfilm-related information includes a display of the number of exposedfilm frames which have been advanced.

Further, the display area for film-related information includes adisplay for lens focal length position.

In a still further aspect of the invention, the display area for apicture-taking mode includes a display for a daylight synchro modetaking mode.

In a still further aspect of the invention, the display area for apicture-taking mode includes display for a macro mode.

In accordance with a still further aspect of the present invention, theindicator unit further includes an operation button array, wherein theat least one switch includes (i) a two-stage switch that operates as aphotometry switch and as a shutter release switch; (ii) a tele switch;and (iii) a wide switch, wherein the two-stage switch, the tele switch,and the wide switch are actuatable by operation of the operation buttonarray, and wherein the means for changing the indication provided by themeans for providing an indication is responsive to operation of theoperation button array to actuate any of the two-stage switch, the teleswitch, and the wide switch to display the focal length.

In another aspect of the invention, the at least one switch includes afilm presence switch, and the means for changing the indication providedby the means for providing an indication is responsive to operation ofthe film presence switch to display an indication of a film-loadingrequest.

In yet another aspect of the invention, the at least one switch includesa film advancement switch, and wherein the means for changing theindication provided by the means for providing an indication isresponsive to operation of the film advancement switch to display anindication that the film is being advanced.

A further object of the present invention is to provide an indicatorunit for a camera including: means for indicating any of a plurality ofitems of camera-related information; means for controlling which of theplurality of items of information is indicated by the means forindicating, including: (i) means for assigning an indication priority toat least one predetermined item of information of the plurality of itemsof camera-related information, for enabling an indication of the atleast one predetermined item of information under predeterminedconditions; (ii) means for overriding the means for assigning anindication priority, for enabling an indication of at least onepredetermined other item of camera-related information under otherpredetermined conditions.

In a particular aspect of the invention, the one predetermined item ofinformation includes the number of exposed film frames which have beenadvanced by the camera.

In another aspect of the invention, the at least one predetermined otheritem of camera-related information includes focal length information.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and additional objects, characteristics, and advantages of thepresent invention will be further described in the following detaileddescription of preferred embodiments, with reference to the accompanyingdrawings, which are given by way of non-limiting examples, in which:

FIG. 1A is a block diagram of a zoom unit constructed according to thepresent invention;

FIG. 1B is a block diagram of the zoom unit of FIG. 1A, wherein the zoomlens is electrically operated;

FIG. 1C is a block diagram of an electronically switchable indicatorunit that displays information that is relevant to a photographer;

FIG. 2 illustrates a front view of a camera constructed according to thepresent invention;

FIG. 3 illustrates a top view of the camera of FIG. 2;

FIG. 4 represents a rear view of the camera of FIG. 2;

FIG. 5A illustrates the rear of the camera shown in FIG. 4, wherein aback cover of the camera is in an open position;

FIG. 5B discloses an LCD display panel that is used with the camera ofthe preferred embodiment;

FIG. 5C illustrates the LCD display panel of FIG. 5B displayingalternative photography information;

FIG. 6 is a schematic perspective view of a lens assembly used in thecamera of FIG. 2, showing the relationship between a cam ring, codeplate and a plurality of brushes;

FIG. 7 is an exploded view of the code plate shown on the lens assemblyin FIG. 6;

FIG. 8 illustrates a control circuit of the camera constructed accordingto the present invention;

FIGS. 9 and 10 illustrate the computer software flowchart diagram for aMAIN program that is executed by a CPU in the camera of FIG. 2;

FIG. 11 illustrates a software flowchart diagram for a POSITION CODEINITIALIZATION subroutine which is called by the MAIN program shown inFIGS. 9 and 10;

FIG. 12 illustrates a software flowchart diagram for a ZOOM CODE INPUTsubroutine that is called by the POSITION CODE INITIALIZATION subroutineof FIG. 11;

FIG. 13 illustrates a software flowchart diagram of a CODE CHECKsubroutine that is called by the POSITION CODE INITIALIZATION subroutineof FIG. 11;

FIG. 14 illustrates a software flowchart diagram of a ZOOM REVERSEROTATION subroutine that is called by the MAIN program shown in FIGS. 9and 10;

FIG. 15 illustrates a software flowchart diagram of a ZOOM FORWARDROTATION subroutine that is called by the MAIN program shown in FIGS. 9and 10;

FIG. 16 illustrates a software flowchart diagram for a ZOOM WIDEsubroutine that is called by the MAIN program shown in FIGS. 9 and 10;

FIG. 17 illustrates a software flowchart diagram for ZOOM TELEsubroutine that is called by the MAIN program shown in FIGS. 9 and 10;

FIG. 18 illustrates a software flowchart diagram for a BACKUP routinethat diverges from the MAIN program shown in FIGS. 9 and 10;

FIG. 19 illustrates a software flowchart diagram for a BAD CHECK CODELOOP routine that diverges from the CODE CHECK subroutine of FIG. 13 andthe BACKUP routine of FIG. 18;

FIG. 20 illustrates a software flowchart diagram for a RESET routinethat is initiated upon initial power-up and also diverges from theBACKUP routine shown in FIG. 18;

FIG. 21 illustrates a software flowchart diagram for a FILM INDICATIONsubroutine that is called by the MAIN program of FIGS. 9 and 10;

FIG. 22 illustrates a flowchart for a series of instructions to performa LOAD operation, this operation diverging from the MAIN program;

FIG. 23 illustrates the instructions for a WIND PULSE CHANGE subroutinewhich is called by the LOAD operation;

FIG. 24 illustrates s software flowchart diagram for determining whetherthe photometric switch SWS in ON;

FIG. 25 illustrates a software flowchart diagram for a LOCK routine thatdiverges from the MAIN program shown in FIGS. 9 and 10;

FIG. 26 graphically illustrates the zooming operation of the lens systemused with the camera that is constructed according to the presentinvention;

FIG. 27A illustrates a MAIN program which is a summary of the flowchartof the MAIN program shown in FIGS. 9 and 10;

FIG. 27B illustrates a software flowchart for a series of instructionsfor a DATA I/O operation that diverges from the MAIN program shown inFIG. 27A;

FIG. 28 is a table that shows the relationship between adistance-measuring step and a lens latch when the camera constructedaccording to the preferred embodiment is in a zoom mode and a macromode;

FIG. 29 illustrates a flowchart for a MACRO TELE SHIFT subroutine thatis called by the DATA I/O operation of FIG. 27B;

FIG. 30 illustrates a flowchart for a LENS LATCH subroutine that iscalled by the DATA I/O operation of FIG. 27B;

FIG. 31 illustrates a flowchart for a series of instructions for aRELEASE LOCK PROCESSING operation that diverges from the DATA I/Ooperation shown in FIG. 27B;

FIG. 32 illustrates a series of instructions for a RELEASE SEQUENCEoperation that diverges from the DATA I/O operation of FIG. 27B;

FIG. 33 illustrates a series of instructions that form a WIND operationwhich diverges from the RELEASE SEQUENCE operation of FIG. 32;

FIG. 34 illustrates a summary of the instruction shown in the MAINprogram illustrated in FIGS. 9 and 10 with additional instructions addedto illustrate the steps involved in a strobe changing operation for astrobe built into the camera constructed according to the presentinvention;

FIG. 35 illustrates the series of instructions that constitute a STROBEAUTOEXPOSURE/AUTOFOCUS operation that diverges from the MAIN programshown in FIG. 34;

FIG. 36 illustrates the series of instructions that comprise a CHARGEoperation that diverges from the MAIN program shown in FIG. 34; and

FIG. 37 illustrates a flowchart for a series of instructions for aRELEASE PROCESSING operation that diverges from the STROBEAUTOEXPOSURE/AUTOFOCUS operation shown in FIG. 35.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1A schematically illustrates the zoom position detecting deviceaccording to the present invention which is described in further detailbelow. Included is a means 15 for outputting a zoom code; a code plate13 that is provided on the circumferential surface of a cam ring 12 toeffect a change in the focal length of a zoom lens; a plurality ofbrushes 14 that are mounted on the camera body in slidable contact withthe code plate 13 so as to generate a relative zoom code based on theconductive condition of the brushes; means 16 for detecting a positionwhich converts the zoom code to a position code corresponding to thefocal length of the zoom lens; means 17 for storing a pattern of changesof the zoom code, the pattern of changes being associated with thezooming operation; means 18 for detecting changes of the zoom code anddetermining if the changes coincide with the pattern of changes; andmeans 19 for prohibiting which examines whether changes of the zoom codeare different from the pattern of changes and, if it is different,whether the changes are due to an electrical separation of at least onebrush with the code plate, in which case the conversion of the zoom codeto a position code is prohibited.

As shown in FIG. 1B, the zoom lens of the present invention can also beelectrically operated. The electrically operated zoom lens furthercomprises means 16' for counting and storing changes of the zoom codefrom the area of the absolute code and storing it in the memory as aposition code that corresponds to the focal length of the lens; means18' for driving the zoom motor 10 so as to change the focal length ofthe zoom lens 11 by controlling the energization of the zoom motor 10 inaccordance with an input from operation switch 17' and the position codestored in the memory; and means 19 for correcting which controls themotor drive means 18' to rotate the cam ring 12 to a position in whichthe zoom code becomes an absolute code when the position of the countmemory means 16' is erased.

In addition, as will be discussed below, the camera includes a means forindicating the focal length of the lens so that an operator of thecamera knows the setting of the zoom lens.

For instance, assume the frame number of the film in the camera is givenpriority for indication purposes on the display as the first piece ofupdatable information which is stored in the first memory, as shown inFIG. 1C. The indication switching means operates to selectively switchthe indication on the display to show the other piece of updatableinformation, such as the focal length of the zoom lens.

With reference to FIGS. 2-5A, in the preferred embodiment of theinvention, the camera comprises a compact type lens shutter camera inwhich a zoom lens 11 and finder system 21 are independent of each other.The front of the camera houses a strobe 22, a CdS sensor 23 forphotometry sensing and a distance measurement device 24, comprising aposition sensor (PSD) 57 and an infrared detector (IRED) 56. The strobe22 illuminates a subject to be photographed, the CdS photo cell 23measures the brightness of the subject, and the infrared emitting diode(IRED) emits infrared rays onto the subject so that the position sensorPSD outputs a position signal according to the distance from the subjectby receiving the infrared light that is reflected from the subject. Thezoom lens 11 is associated with a movable lens barrel 27 which movesrelative to a fixed lens barrel 26 connected to camera body 25. Themovable lens barrel 27 is displaced between a storage position (shown asa broken line in FIG. 3) and a macro extremity (shown by a solid line inFIG. 3). In tis embodiment, the focal length of the zoom lens 11 isvariable from approximately 38 mm to 60 mm in the zoom range. Inaddition, the camera of the present invention has a macro position and alock position.

As shown in FIG. 3 in particular, the upper portion of the cameracontains a generally triangularly shaped operation button array 28 whichis also used as the zoom button. Front part 28a of the operation buttonarray 28 comprises a 2-stage switch that operates as a photometry switchSWS and shutter release switch SWR. One rear button 28b of the operationbutton array 28 on the rear side comprises a tele switch SWT forcontrolling the zoom lens 11, while a second rear button 28c of theoperation button array 28 comprises a wide switch SWW for controllingthe zoom lens 11. These three switches 28a, 28b and 28c are interrelatedin such a fashion that when one switch is operated, the other twoswitches cannot be operated. Depressing the shutter button 28 halfwayactivates the photometry switch SWS, while fully depressing the shutterbutton 28 activates the release switch SWR.

By depressing the portion of the operation button array above the teleswitch SWT and, consequently, tilting the generally triangular memberdownwardly thereat, the zoom motor 10 is rotated in a direction thatcauses the zoom lens 11 to extend from the camera body 1. By depressingthe portion of the operation button array above the wide switch SWW thezoom motor 10 is rotated in an opposite direction, such that the zoomlens 11 is retracted into the camera body 1. The rotation of the zoommotor 10 is controlled by the main CPU, which executes a sequence ofinstructions based upon which switch, SWT or SWW, is depressed.

As shown in FIGS. 4 and 5A in particular, the rear portion of the camerabody 25 comprises a back cover 29 (film compartment cover), a mainswitch 30, a mode switch 31, an LCD panel 32, a back cover open/closelever 36, a red lamp indicator (LED) Rd, and a green lamp indicator(LED) Gd. A film switch 33 is operable to detect the presence of film,while a wind pulse switch 34 is operable to generate a wind pulse inresponse to the advancing of the film. The film loading detector switch33 is sunk into wall 33a inside the camera when the film cartridge(patron) is placed in film cartridge compartment 35a, the leading end ofthe film is put on spool 35 with its perforation in contact with thefilm advance detector switch 34, on the back cover 3 is closed. The filmpresence detector switch 33 is turned off when it is fully sunk into thewall 33a. When the film presence detector switch 22 is in the off state,the film is ready to be advanced.

The red lamp indicator Rd blinks when the photometric switch SWS isdepressed and strobe emission is needed but is not ready. When theshutter release button SWR is pressed and the strobe 22 emits light, thered lamp indicator Rd is continuously illuminated (that is, the red lampindicator Rd has a 100 percent ON duty cycle). The green lamp indicatorGd blinks if the subject is too close when the photometric switch SWS isdepressed and it is fully illuminated (as described above for the redlamp indicator Rd) when the subject is within the proper distance forthe taking of a flash photograph.

The back cover 29 is opened by sliding the back cover open/close lever36 in the direction of arrow A. The main switch 30 comprises a threeposition slidable switch, having a lock position SWL, a zoom positionSWZ and a macro position SWM. When the main switch 30 is moved in thedirection of arrow B, from the lock position SWL to the zoom positionSWZ, or from the lock position SWL to the macro position SWM, power forthe camera's components, schematically shown in FIG. 8, such as a motordrive circuit 500, strobe circuit 600, etc., are turned on by theapplication of electrical power to a main CPU 100.

The LCD panel 32 operates under the control of the main CPU and has thecapability of displaying a free wind-up mark, which indicates therequest for a free film feed; a patron mark, which indicates the loadingof the film; the frame number of the film; and a focal length valueindicating the position of the zoom lens.

A switching operation functions to switch the data that is displayed onthe LCD panel 32. For instance, as shown in FIG. 5B, the LCD displaypanel 32 includes a film status indicator area 32a for indicatingfilm-related information 32r, a mode indicator area 32b for indicatingthe photographing mode of the camera, such as a normal mode 32s and abattery status indicator area 32c for indicating the condition of camerabattery 32t. In the illustration shown in FIG. 5B, the film statusindicator 32a serves to initially indicate a blank-shot film advancerequest L_(d) (which is as cylindrical film roll case representing theloading of film) when a film is first loaded into the camera, the filmframe number, or alternatively, the focal length of the zoom lens 11.

FIG. 5C illustrates the LCD panel 32 indicating alternative information.In this illustration, the film status indicator area 32a has beenchanged to indicate the focal length of the zoom lens, while the modeindicator area 32b has been changed to indicate a daytime synchronizedmode 32x.

The battery status indicator area 32c indicates the condition of thecamera battery to the photographer. The camera battery 32t has twoindicators 32y and 32z. When a fully charged battery is inserted intothe camera, the outline of the camera battery 32t and the two indicators32y and 32z are illuminated. When the camera battery is partiallydischarged, the outline of the camera battery 32t and only one indicator32z are illuminated. When the camera battery voltage is below apredetermined level (or is fully discharged), every figure displayed inthe LCD panel blinks. This blinking feature alerts the photographer toreplace the battery.

The main CPU controls a means for indicating a loading request forforcing an indication of the blank-shot film advance request L_(d) onthe liquid crystal panel 32, when the film presence detector switch 33detects the absence of a film in the camera. The main CPU furthercontrols the liquid crystal panel 32 so as give display priority to theframe number of the film loaded in the camera. With respect toindicating the status of the film and the focal length of the zoom lens11 on the display panel 32, the main CPU gives priority to the filmframe number. This first piece of updatable information is stored in afirst memory. The indication of a second function, such as focal lengthinformation, comprises a second piece of updatable information that isalso stored in a memory means. The display of the second function on thedisplay panel 32 replaces the display of the first function in responseto the operation of the tele switch SWT, wide switch SWW or lightmeasuring switch SWS. The main CPU also receives inputs from the filmpresence detecting switch 33, the film advance detector switch 34,battery loading information from the battery presence switch SWB, zoomcode information and DX contact information which indicates thesensitivity of the film.

FIG. 1C schematically illustrates how the various items of informationcan be displayed in a limited indication area. An indicator controlmeans enables a first type of information to be stored in the firstmemory and another type of information to be stored in a second memory.The information in the first memory is given priority over that in thesecond memory so that the information in the first memory is displayedin the limited indication area unless a switch that is responsive to thesecond type of information is operated.

As shown in FIG. 8, the motor drive circuit 500 controls the zoom motor10 and a film winding motor 510. The motor drive circuit 500 iscontrolled by the main CPU 100. The mode select button 31 operates toswitch between a normal photographing mode and a daytime synchrophotographing mode. When the mode select button 31 is switched to thenormal photographing mode, the daytime synchro photographing mode isselected. When the mode select button 31 is switched to the daytimesynchro photographing mode, the normal photographing mode is selected.The selected mode is displayed on the LCD panel 32.

As noted above, the main CPU controls the function of advancing the filmfor a predetermined number of blank-shots when a new roll of film isplaced in the camera in accordance with the loading request indicationcontrol means, with which the blank-shot film advances are executed byoperating a film advance motor 510 in dependence upon the operation ofthe main switch 30 and the release switch SWR. The operation of the filmadvance motor 510 is stopped when the predetermined number of blank-shotframes have been taken, in response to the output detection of the filmadvance detector switch 34.

Winding axis 35 is the spool axis upon which the film is wound on as thefilm advances from one frame to another.

The main CPU 100 performs the transfer of information with a sub CPU viaa drive IC. In the embodiment of the preferred invention, the main CPU,sub CPU, drive IC and autofocus IC have been incorporated into the mainCPU using system integrated very large scale integrated circuitry(VLSIC) to create a custom IC. The sub CPU functions to transferphotometry information from a photometric element 23 and distancemeasurement section 24 to the main CPU 100. In addition, the sub CPUalso controls the transfer of information with an autofocus IC. Theautofocus IC controls the emission of an infrared light emitting diode(LED) and transfer output information from a position sensor (PSD),which receives the infrared light reflected from a subject to providedistance measurement information to the sub CPU.

As shown in FIG. 8, the camera comprises a photometric switch SWS and ashutter release switch SWR (both of which are activated by depressingthe shutter button 28a), a power source 300, and a strobe circuit 600which causes the strobe 22 to flash. The strobe circuit includes acapacitor (not illustrated) which is charged by a voltage boostercircuit and boost circuit. Current charging this capacitor is sent tostrobe 22 so that it flashes.

Referring to FIG. 6, cam ring 12 is installed around the zoom lens 11and is linked to zoom motor 10 through sector gear 12a and pinion 10a,which advances and withdraws the zoom lens 11 according to the rotationof the zoom motor 10 by a cam mechanism, which is not shown in thedrawing.

In the camera constructed according to the present invention,information concerning a change in the focal length of the lens 11, achange in the open-aperture F-number according to the focal lengthchange and a determination as to whether the lens is at the wideextremity, the tele extremity, the macro photographing position, or thelock position, is automatically detected for performing variousoperations according to the detected information. To obtain the requiredinformation, the code plate 13 is secured to the circumference of camring 12, while four brush terminals 14 (ZC0, ZC1, ZC2, and GND) contactthe code plate 13. One brush operates as a ground terminal (GND), whilethe remaining three brushes (ZC0, ZC1 and ZC2) are used for codedetection.

FIG. 7 is an exploded "flattened" view of the code plate 13. Whenterminals ZC0, ZC1 and ZC2 come in contact with a conductive land of thecode plate, shown by hatches in the drawing, a signal "0" is generated,while when a brush does not contact a conductive land, a signal "1" isgenerated. Thus, a three-bit information detection signal generated bythe conductive relationship of the brushes ZC1-ZC3 with the ground brushGND correspond to a zoom code ZC.

Shown below the code plate 13 (in FIG. 7) is a position code POS thatcorresponds to the zoom code ZC, as shown in Table 1. The position codePOS represents a hexadecimal value from "0_(H) " to "E_(H) ".

In the camera, there are 15 detection steps that correspond to the focallength of the lens. Hence, there are 15 position code POS. It should benoted that the focal length indication is set to 6 steps that correspondto the position code POS.

To detect the 15 positions using three brushes, it is necessary tocreate a relative code which holds the zoom code in common for differentstep positions. In the embodiment, the absolute code is set by providinga one to one correspondence between the part where the position code POSequals "0_(H) ", "1_(H) ", "D_(H) " and "E_(H) " and the zoom code ZCequals "0", "1", "2" and "3", while the relative code is set byproviding a repeated correspondence between the position code equalling"2_(H) " to "C_(H) " and the zoom code ZC equalling "4" to "7".

When POS equals "0_(H) ", the zoom lens 11 is drawn into the fixed lensbarrel 26 and the front of the lens 11 is covered by a barrier (notshown) to set the lens to a lock mode. A position code POS of "2_(H) "to "C_(H) " denotes a zoom capable range, while a position code POS of"E_(H) " indicates a macro position that is used for close-upphotography. The boundary section between the lock position and the zoomrange, as well as the zoom range and the macro position denotes a stopprohibiting range.

                  TABLE 1                                                         ______________________________________                                        POS        0  1  2  3  4  5  6  7  8  9  A B C D E                            ______________________________________                                        ZC2        0  0  1  1  1  1  1  1  1  1  1  1  1  0  0                        ZC1        1  0  0  0  1  1  0  0  1  1  0  0  1  1  0                        ZC0        1  1  1  0  0  1  1  0  0  1  1  0  0  0  0                        ZC         3  1  5  4  6  7  5  4  6  7  5  4  6  2  0                        Indication (mm)                                                                          38 38 38  42   46  50  55  60 60 60 60                             ______________________________________                                        LOCK STOP                                                                              Zooming area         STOP Macro                                      pro-                          pro-                                            hib-                          hib-                                            ited                          ited                                            Absolute Relative code        Absolute                                        Code                          Code                                            ______________________________________                                    

The circuit configuration used with the camera of the present inventionwill be further explained with reference to FIG. 8. The operation of thecamera will be explained with reference to a plurality of flowcharts,shown in FIGS. 9-23. In the following description, the details for thezoom-related processing concerning this invention is explained, whileprocessing relating to the shutter control or the advancement of thefilm will only be briefly described.

A main CPU 100 has four serial signal lines. A shutter AF unit, whichperforms shutter-related processing, is connected to the four serialsignal lines. Battery 300 supplies power to the main CPU 100 via aregulator 310. The LCD panel 32, zoom motor 10 and other components ofthe camera are controlled according to the inputs from theabove-mentioned switches. A backup capacitor 320 supplies current to themain CPU 100 when the battery 300 is removed from the camera.

A motor operation circuit 400 comprises a plurality of PNP transistors401-404, NPN transistors 405 and 406 and multiple biasing resistors,which function to control the forward and reverse rotation of the lens,as well as the stopping of the zoom motor 10 according to four-bitsignals FOW N, REV P, REV N and FOW P outputting from the main CPU 100,as shown in Tables 2 and 3.

The zoom motor 10 rotates in a forward direction to cause the zoom lens11 to extend out of the camera body 25 so as to change the focal lengthof the lens to the tele range. When the zoom motor rotates in a reversedirection, the zoom lens 11 is drawn into the camera body so as tochange the focal length of the lens 11 to the wide extremity.

                  TABLE 2                                                         ______________________________________                                        Normal Rotation                                                               FOW N     FOW P    REV P    REV N                                             ______________________________________                                        1                                    Open                                     2   ON        ON                     Normal rotation                          3                                    Open                                     4   ON                        ON     Brake                                    5                                    Open                                     ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Reverse Rotation                                                              FOW N     FOW P    REV P    REV N                                             ______________________________________                                        1                                    Open                                     2                      ON     ON     Normal rotation                          3                                    Open                                     4   ON                        ON     Brake                                    5                                    Open                                     ______________________________________                                    

The following switches provide information to the main CPU 100;

(1) Lock switch SWL, which is set to ON when the main switch 30 is setto the lock position;

(2) Macro switch SWM, which is set to ON when the main switch 30 is setto the macro position;

(3) Film switch SWF (element 33 in FIG. 5A), which is depressed by thefilm loaded into the camera, and being set to OFF when the back cover 29is closed;

(4) Battery switch SWB, which is set to ON by mechanically detecting thepresence of a battery;

(5) Brushes ZC0, ZC1 and ZC2, which come in contact with the code plate13 to detect zoom codes ZC (these brushes are not technically switches,however, as they perform as switches in the circuit, they are expressedas switches for convenience);

(6) Photometry switch SWS, which is set to ON by depressing the frontswitch 28a of the operation button array 28 by one step;

(7) Release switch SWR, which is set to ON by depressing the frontswitch 28a of the operation button array 28 by two steps;

(8) Zoom tele switch SWT, which is set to ON by depressing rear switch28b of the operation button array 28; and

(9) Zoom wide switch SWW, which is set to ON by depressing rear switch28c of the shutter button 28.

The main CPU 100 performs the following functions by executing storedprograms;

(1) Zoom control based on the conductive condition of brushes;

(2) Control the zoom motor 10 according to inputs from the switches andthe zoom code;

(3) Hold and store in memory changes in the zoom code as the positioncode by counting the changes from the absolute code section;

(4) Hold the pattern of changes of code information associated with thezooming operation;

(5) Detect changes in the zoom code and examine whether or not thechange coincides with the pattern of changes;

(6) If the change in the zoom code is different from the pattern ofchanges, determine whether the change is due to a separation of at leastone brush from the code plate and, if the change is due to a brushseparation, prohibit the conversion of the zoom code to a position codeafter the detected change; and

(7) Control the zoom motor so that the cam ring is turned to a positionin which the zoom code becomes an absolute code when the memory forcounting is erased.

MAIN Program

The MAIN program flowchart is illustrated in FIGS. 9 and 10. The MAINprogram specifies the basic operation of the camera. Associatedprograms, called subroutines, are executed after being called by aninstruction of the MAIN program. Steps 1-22 of FIG. 27A is a summaryflowchart of the MAIN program illustrated in FIGS. 9 and 10. FIG. 27Adiscloses the instructions necessary to perform a DATA I/O operation,whereas this operation has been summarized in steps 51-64 of FIG. 10.The instructions that are shown in the MAIN program flowchart of FIG.27A have been labelled such that they correspond to the instructionslisted in FIGS. 9 and 10.

In step (referred to in the drawings as "S" before an instructionnumber) 1, the status of each switch is inputted to the main CPU 100,which stores the detected settings in a memory so as to provide a seriesof initial switch values. A position flag F_(POS) is examined todetermine if the flag has been set to 1. The position flag indicates thereliability of the position code. If the flag is set to 1, processingadvances to step 3. If the flag is set to 0, a POSITION CODEINITIALIZATION (POS INI) subroutine is executed at step 4, which will bedescribed below. The POS INI subroutine is run when the relative code isused for the POS detection and has the characteristics of a componentspecific to this invention.

In step 3, the status of the switches are inputted once more. Thepurpose of this step is to detect any dynamic changes in the setting ofthe switches by comparing the re-read settings with the data stored inmemory.

In step 5, battery switch SWB is examined to determine if it is set toON. If this switch is set to OFF, that is, if the battery is removed,processing advances to step 6 to diverge to a BACKUP series ofinstructions, to be described below. The camera constructed according tothe present invention keeps the data stored in memory for a certainperiod of time if the battery 300 is removed (i.e., due to a batteryreplacement operation) by means of the energy that is stored in thecapacitor 320. When the backup power supply is used (i.e., capacitor320), operation requiring a large power consumption must be prohibited.This is accomplished by diverging to the BACKUP instructions.

When operating the camera, the first step is to load the film. Automaticfilm loading is performed by pulling out the film to the point where itstip end is laid on winding axis 35. To control the film loading, a filmloading request flag F_(LDRQ) and a loading end flag F_(LDEND) are used.These flag operations are performed in step 257 of the BACKUPinstructions (FIG. 18), step 309 of a series of instructions to performa RESET operation (FIG. 20), step 325 of a series of instructions toperform a REWIND operation (FIG. 22) and steps 358, 360 and 361 of aseries of instructions to perform a LOCK operation (FIG. 23), as well asin the MAIN program.

When it has been determined that the battery is loaded (step 5), steps7-14 are performed to determine whether the film switch SWF is in acondition whereby it can be estimated from the film loading flags. Ifthe condition is different from what was estimated, an indication of thefilm frame is shown on the LCD panel 32, while if it is the same as whatwas estimated, the previous indication (namely, either the focal lengthor film frame indication) is maintained on the LCD panel 32 andprocessing continues to step 15.

Thus, in step 7, it is determined whether the loading end flag F_(LDEND)is set to 1. This flag is initially set to 0, meaning that the filmloading has not yet taken place. If this flag is set to 0, adetermination of whether the loading request flag F_(LDRQ) is set to 1is made in step 8. F_(LDRQ) is initially set to 0.

When it is decided that both flags are negative (i.e., set to 0), thefilm switch SWF is checked in step 9. When the end of the film is pulledout so that it is placed on the winding axis 35 and the back cover 29 isclosed, film switch SWF is set to OFF and the loading request flagF_(LDRQ) is set in step 10 so that the film loading operation is readyto be performed.

When this flag is set and the program loops back to this step again, thetest performed in step 8 is positive. When the film loading is complete,the decision of step 7 is positive. Therefore, the same test is made instep 11 as was performed in step 9. The film switch SWF is set to ONafter the flags F_(LDRQ) or F_(LDEND) have been set when the back cover29 is opened or the film has been rewound. In the former case, flagsF_(LDRQ) and F_(LDEND) are cleared (steps 12 and 13) and then the filmstatus is indicated on the LCD panel 32 (step 14). The film indicationis shown with priority given to the focal length indication, except whenthe LCD panel is temporarily switched to display another indication.

In step 15, a test is made to determine if the loading request flagF_(LDRQ) is set to 1. If this flag is set to 1, the status for the macroswitch SWM and the lock switch SWL are tested (steps 16 and 17) todetermine whether they have changes since their setting was stored inmemory. If they have changed, processing diverges to a LOAD operation(step 18). If there have been no changes, the MAIN program proceeds tostep 19.

In step 19, the status of the lock switch SWL is judged by examining thedata input for this switch that was obtained from step 3. The lockswitch SWL is set to ON when the camera is placed in a storage ornon-use condition. In this case, the position code POS is examined todetermine if it is equal to "0_(H) ", that is, whether the lens beenmoved to the lock position (step 20). If the lens is already in the lockposition, processing advances to step 21 and the LOCK subroutine iscalled. If the lens is not in the lock position, a ZM REV subroutine(step 22) is performed so as to reverse the rotation of the zoom motor,retracting the zoom lens into the camera body into the lock position.

When the lock switch SWL is set to OFF, the following operations areperformed:

First, in step 23, the status of the macro switch SWM is examined. Ifthe macro switch SWM is set to ON, as is required to set the lens intothe position needed for close-up photography, an examination is made ofthe position code POS (step 24) to determine if it is equal to "E_(H) ".When POS equals "E_(H) ", the lens is already in the macro position.Therefore, processing advances to point A shown in FIG. 10.

If POS is not equal to "E_(H) ", processing advances to steps 25 and 26,wherein an indication related counter SCANT is set to 8 and a ZM FOWsubroutine is called to rotate the zoom motor in a forward direction.Step 25 is a timer instruction which causes the focal length of the lensto be displayed on the LCD panel for a period of one second. Thereafter,the MAIN program is re-executed.

When it is determined that the macro switch SWM is set to OFF in step23, the lens needs to be in the range where POS equals "2_(H) "-"C_(H)". That is, the lens needs to be in the zoom range. Therefore, if theposition code POS is greater than or equal to "2_(H) " (step 27), thenext question to be answered is whether the position code POS is lessthan or equal to "C_(H) " (step 28).

When POS is less than "2_(H) " (that is, POS equals "0_(H) " or "1_(H)"), the lens is in the lock position or the boundary area between thelock position and the zoom range. Therefore, to pull the lens out to thezoom range to allow photographing, the above-mentioned operation to setthe counter of step 25 is performed. Then, the processing for the zoommotor forward rotation of step 26 is carried out. When POS is largerthan "C_(H) ", the lens is in the macro position or the boundary areabetween the macro extremity and the zoom range. Therefore, after theindication counter SCANT is set to "8", in step 29A, the subroutine forthe zoom motor reverse rotation is called in step 22.

When the judgment of steps 27 and 28 are both affirmative, the lens isin the zoom range. Thus, the condition of the zoom wide switch SWW isexamined (step 29B). When this switch is set to ON, the indication onthe LCD panel is switched from the film indication to display the focallength of the lens (step 30) and the indication counter SCANT is set to"8" (step 31). Then, wide extremity flag F_(WIDE) is examined todetermine if the lens is at the wide extremity (step 32). The wideextremity flag F_(WIDE) is set to a value in step 116 of the POS INIsubroutine (FIG. 11), step 162 of the ZM REV subroutine, steps 185 and189 of the ZXM FOR subroutine and step 211 of a WIDE subroutine. If thisflag is set to 1, the lens is already at the wide extremity and cannotbe moved any further. Therefore, processing advances to point A, shownin FIG. 10. If the wide extremity flag F_(WIDE) is set to 0, the WIDEsubroutine is called at step 33.

When it is determined that the wide switch SWW is set to OFF in step29B, processing advances to point B, shown in FIG. 10, so that thestatus of the zoom tele switch SWT can be determined. When the teleswitch SWT is set to ON, the LCD display is switched to indicate thefocal length of the lens (step 35) and the counter SCANT is set to avalue of "8" (step 35). Thereafter, the position code POS is examined todetermine if it is equal to "C_(H) ". When POS is equal to "C_(H) ", thelens is already at the tele extremity. Therefore, processing jumps tostep 49. When POS is not equal to "C_(H) ", a TELE subroutine is calledat step 38 of the MAIN program.

When the tele switch and wide switch are not set to ON, processingadvances to step 39. In steps 39-42, the display of the LCD panel isswitched according to the indication counter SCANT. In step 39, thecounter SCANT is checked to see if it has been set to "0". As describedabove, SCANT is set to "8" when the zoom switches SWW and SWT are set toON. If SCANT is not equal to "0", one count is subtracted from theindication counter SCANT (step 40). The MAIN program executes a loopbetween steps 2 and 50 every 125 milliseconds (ms). Therefore, a periodof one second can be counted by successively reducing by "1" the valueof the counter SCANT, which has previously been set to a value of "8".

Step 41 determines whether the indication counter SCANT has become "0"as a result of the above subtraction operation. If the counter is "0",one second has passed. When SCANT becomes "0", the indication on the LCDpanel is switched from indicating the focal length of the lens toindicating the film frame number (step 42), while when it is not equalto "0", step 42 is skipped and the focal length indication of the lensis kept on the LCD display.

When it is judged that SCANT equals "0" in step 39, steps 40-42 areskipped.

In step 43, the loading request flag F_(LDRQ) is checked to see if it isset to 1. If it is set to 1, the current setting of the release switchSWR is compared to its memory setting to determine if there has been achange (steps 44 and 45). When the release switch SWR has changed frombeing OFF to being ON, the LOAD instructions are executed by divergingfrom step 46. When the status of the release switch SWR has not changedor it has changed from ON to OFF, processing returns to the MAINprogram. However, when the loading request flag F_(LDRQ) is set to 1,the testing of the status of the photometry SWS in step 47 is notperformed. Therefore, the operation of the photometry switch SWS has noeffect on the camera.

When the loading request flag F_(LDRQ) is set to 0, the setting of thephotometry switch SWS is compared to its setting that is stored inmemory (step 48) to determine if it has changed. If there is no change,or the setting has changed from ON to OFF, step 49 is executed so as torewrite the switch data into the memory in step 3, after pausing for aperiod of 125 ms (step 50) before looping back to step 2.

Also, in the case where the macro switch SWM is set to ON and the lensis in the macro position or the wide switch SWW is set to ON and thelens is in the wide extremity or the tele switch SWT is set to ON andthe lens being is in the tele extremity, processing advances to step 49.

When the photometry switch SWS is changed from OFF to ON, the indicationcounter SCANT is set to "1" (step 51) and the indication on the LCDpanel is switched to display the focal length of the lens (step 52).

In step 53, exposure value Ev is calculated from the brightnessinformation of a subject that is obtained from the Cds sensor and thefilm sensitivity that is calculated from the film DX code.

In steps 54-64, the status of the photometry switch SWS, battery switchSWB, release switch SWR and lock switch SWL are inputted andsuccessively tested to determine if they are ON or OFF. First, in step55, the status of the photometry switch SWS is determined. If thisswitch is set to OFF, processing returns to the start of the MAINprogram. As the indication counter SCANT was set to "1" in step 51,SCANT becomes "0" in step 40 for the first loop and the focal lengthindication on the LCD panel is switched to indicate the number of filmframes in step 42.

When the photometry switch SWS is ON (step 55), the battery switch SWBis tested to determine if it is ON (step 56). When the battery switchSWB is OFF, the BACKUP instructions are executed by diverging from step57, while when the switch is ON, step 58 is executed to determine thesetting of the release switch SWR.

When the release switch is set to ON, an EXPOSURE subroutine is calledin step 59. This subroutine controls the operation of the camerashutter. Thereafter, a WIND subroutine is called in step 60 to advancethe film by one frame. After the WIND subroutine has completed, adecision needs to be made as to whether to rewind the film (step 61).When the winding is normally finished, step 61 is negative. Thus,processing returns to the start of the MAIN program. If it is determinedthat the end of the film has been reached, a series of instructions toexecute a REWIND operation are performed by diverging from step 62. Ifthe release switch SWR is determined as being OFF in step 58, the statusof the lock switch SWL is checked in step 64. When the lock switch SWLis ON, processing returns to the start of the MAIN program, while whenthe lock switch is OFF, processing loops back to step 54.

By the above explanation, each step of the MAIN program has beendescribed. The following discussion will explain the operations that areperformed by the various subroutines that are called by the MAINprogram.

POSITION CODE INITIALIZATION (POS INI) Subroutine

FIG. 11 illustrates the initialization operations called for in step 4of the MAIN program. Position code flag F_(POS) is set to 0 when a RESETsubroutine (shown in FIG. 20) is called or the zoom code ZC shows anabnormal value during a CODE CHECK subroutine (shown in FIG. 13). In theformer case, the subroutine is executed the first time a battery isinserted into the camera, or where the battery is removed from thecamera and not replaced within approximately seventeen minutes.

As the backup capacitor 320 current is usually lower than that requiredto maintain the camera memory after the battery is removed and left outof the camera for a period exceeding seventeen minutes, the cameraconstructed according to the present invention is designed to clear itsmemory when this situation occurs.

The initialization operation is intended to move the lens from the zoomrange, where the zoom code is a relative code, through the wideextremity section to the absolute code section so as to restart thecount for the amount of the lens movement from the absolute codesection.

Accordingly, the first instruction that is executed (step 101) is toinput the zoom code ZC based upon the conductive condition of thebrushes that are in contact with the code plate. This is accomplished bycalling a ZOOM CODE INITIALIZATION (AC IN) subroutine, which isillustrated in FIG. 12.

In step 102, the position code POS is tentatively set according to theinput zoom code ZC. In addition, the change estimation values ZC FOW andZC REV of the zoom code and tentative zoom code are stored in thecamera's memory.

As shown in Table 1, the fifteen-step position code POS is obtained froma three-bit eight-step zoom code ZC. Accordingly, the position code POSis determined from the particular relationship of the zoom code ZCvalues to the position code POS values. Specifically, the "absolute"values of the zoom code ZC ("0", "1", "2", and "3") correspond in aone-to-one relationship with position code POS values of "0_(H) ","1_(H) ", and "E_(H) " and the "relative" code ZC values ("4", "5", "6",and "7") correspond in a multiple-to-one relationship with POS values of"2_(H) "-"C_(H) ".

In the relative code section, position code POS equalling "3_(H) ","7_(H) " or "B_(H) " corresponds to a zoom code ZC of "4"; POS equalling"2_(H) ", "6_(H) ", or "A_(H) " corresponds to a zoom code ZC of "5";POS equalling "4_(H) ", "8_(H) ", or "C_(H) " corresponds to a zoom codeZC of "6"; and POS equalling "5_(H) " or "9_(H) " corresponds to a zoomcode ZC of "7". The temporary setting of the position code POS forciblysets the zoom code to "4", "5", "6" or "7", corresponding to therelative code "B_(H) ", "A_(H) ", "C_(H) "or "9_(H) ", respectively.When the photographing lens is in the range of POS equals " 2_(H)"-"8_(H) ", the value different from that for the actual lens positionis set.

The zoom code value, which is supposed to change when the lens zoom tothe tele or the wide extremity, is set for a change estimation value ZCFOW and ZC REV, respectively. However, this value is rewritten, togetherwith the change of the position code POS in the CODE CHECK subroutine.

In step 102 of this subroutine, when the zoom code a zoom code ZC of"7". The temporary setting of the position code tentatively set to"A_(H) " and as a result, ZC FOW is set to "4" and ZC REV is set to "7".

In step 103, the output of terminal ZC2 is checked to determine if it isequal to 0. As shown in Table 1, the output of terminal ZC2 becomes 0when the zoom code ZC is an absolute code. In the present instance, thetemporary setting of the position code POS is correctly set. Thus, thesubroutine sets the POS flag F_(POS) to 1 and then returns to the MAINprogram.

When the output of terminal ZC2 is 1, the zoom code ZC is the relativecode and the temporarily set position code POS may not coincide with theactual position of the lens. Therefore, the zoom motor is rotated in thereverse direction (step 105) to move the lens into the absolute codesection adjacent the wide extremity.

In step 106, the indication prohibition flag F_(NODSP) is set to 1. Thisflag is used to determine if the focal length of the lens should beindicated when the CODE CHECK subroutine (to be discussed below) isexecuted. When this flag is set to 1, an incorrect focal lengthindication, which occurs when the temporarily set position code POS doesnot coincide with the actual photographing lens position, is prohibitedfrom being displayed on the LCD panel. This flag is also used for theWIDE subroutine, which will also be discussed below.

In step 107, a CODE CHECK (CODE CHK) subroutine (see FIG. 13) is calledto verify the position code. Processing loops through steps 107 and 108until the position code POS is equal to "1_(H) ". When the position codePOS is equal to "1_(H) ", step 109 is executed so as to introduce adelay period of t₁ ms before the zoom motor is activated to rotate inthe forward direction so as to eliminate backlash of the mechanicalsystem.

Thereafter, the CODE CHECK subroutine is re-run (step 111), a pluralityof times if necessary, until the position code POS is equal to "2_(H) "(step 112). When the position code is equal to "2_(H) ", the indicationprohibition flag F_(NODSP) is set to 0 (step 113) and the zoom motor isstopped in step 114.

Finally, the position code flag F_(POS) and wide extremity flag F_(WIDE)are set to 1 (steps 115 and 116) prior to returning to the MAIN program.

ZOOM CODE INPUT (ZC IN) Subroutine

FIG. 12 shows the ZOOM CODE INPUT subroutine that is performed in thePOSITION CODE INITIALIZATION subroutine and the CODE CHECK subroutine.

This subroutine improves the reliability of the zoom code that isdetected by the interfacing of the brush terminals ZC0, ZC1 and ZC2 withthe code plate. The outputs of the brushes are compared by repeating theinput of the zoom code ten times. When the results coincide three times,the zoom code for these results are defined.

When considering the contact relationship between the code plate and thebrush terminals, an OFF (signal level "1") signal may be detected due toa momentary separation of a terminal, when the position should really bean ON (signal level "0") signal. Therefore, the detection results areelectrically AND'ed together and the particular terminal is consideredas being conductive if it is detected as conductive at least once inevery ten tests. This prevents a brush terminal from being incorrectlyread due to the momentary separation of a terminal with the code plate.

When this subroutine is called, the zoom code ZC stored in REGISTER 2,i.e., ZCREG2, of the memory is read and a Z counter is set to "3". Thenthe AND'ed result obtained by inputting the zoom code ten times isstored in REGISTER 1, ZCREG1, (steps 120-122). The value of REGISTER 1is then compared with that of REGISTER 2 (step 123). If the tworegisters are different, the value of REGISTER 1 is moved to REGISTER 2in step 124.

In steps 124-126, the Z counter is set to "1" and the subroutine isplaced in a standby mode for 500 microseconds (us) before another zoomcode is inputted. When the detection result of this cycle is the same asthat of the previous cycle, REGISTER 2 becomes equal to REGISTER 1.Therefore, the Z counter is examined (step 127) to decide if it is equalto "3". When the Z counter is not equal to "3", it is incremented by "1"(step 128) and processing returns to step 122 after a pause of 500 us.

When the Z counter is equal to "3" (in step 127), meaning that REGISTER1 has been equal to REGISTER 2 for three successive cycles of steps 122and 123 after the zoom code ZC has shown different values from the zoomcode memory, the value of REGISTER 2 is defined as the zoom code ZC(step 129') and processing returns to the point from which ZC INsubroutine was called.

CODE CHECK (CODE CHK) Subroutine

FIG. 13 illustrates the CODE CHECK subroutine which changes the positioncode POS according to the zoom code ZC, which itself changes following azooming operation. This subroutine is frequently used in thezoom-related processing shown in FIGS. 14-17, in addition to theabove-mentioned POSITION CODE INITIALIZATION subroutine.

In step 130, data relating to the lock switch SWL, macro switch SWM,battery switch SWB, wide switch SWW and tele switch SWT are inputted. Instep 131, the status of the battery switch SWB is determined. If thisswitch is OFF, the brake is applied to the zoom motor (step 132),register stack processing of the CPU 100 is performed (step 133) andprocessing diverges to the BACKUP instructions, shown in FIG. 18.

When the battery switch is ON, the zoom code ZC is inputted by executingthe above-described ZOOM CODE INPUT subroutine (step 134). Thereafter, acode change flag F_(CHNG) is cleared and set to 0 (step 135) prior tocomparing the content of the zoom code ZC and the zoom code stored inmemory (step 136). The code change flag F_(CHNG) is used only for thisCODE CHECK subroutine to determine whether the position code POS hasbeen rewritten in the zoom related processing.

If the zoom code is equal to the value stored in memory, the subroutineexits, returning to the point from which it was called. However, as thezoom motor rotates, the zoom code value becomes different from thatstored in memory. When the zoom code is different from that stored inmemory, it is necessary to decide if the zoom motor is rotating in theforward direction (step 137).

When the zoom motor is rotating in the reverse direction, it isdetermined whether the changed zoom code ZC coincides with the changeestimation value ZC REV (step 138). When this CODE CHECK subroutine iscalled in the zoom operations shown in FIGS. 14-17, the changed zoomcode normally coincides with the changed estimation value. Accordingly,in step 139, the value "1_(H) " is subtracted from the position codePOS, the zoom code stored in memory is rewritten to the value obtainedafter the zoom lens has moved and the change estimation values ZC FOWand ZC REV are reset to correspond to the position code POS obtainedafter the subroutine is performed. The value of the indicationprohibition flag F_(NODSP) is then examined to determine if it has beenset to 1. If this flag has been set to a value of 0, the focal length ofthe lens is indicated on the display panel (step 141). When the value ofthe prohibition flag is set to 1, step 141 is skipped. Regardless ofwhether the focal length of the lens is displayed or not, the codechange flag F_(CHNG) is then set to 1 in step 142 before the subroutinereturns to where it was called.

However, when the CODE CHECK subroutine is called in step 107 of thePOSITION CODE INITIALIZATION subroutine (FIG. 11), the zoom code afterthe lens has moved may be different from the change estimation value. Inthe same way as that for the above-mentioned example, when thetemporarily set POS is "A_(H) ", ZC REV is "7", ZC FOW is "4", whilewhen the actual lens position before changing is POS equals "2_(H) ",the zoom code ZC after the lens moves becomes equal to "1" for a changecode estimation ZC REV of "7". As a result, the two are not equal andprocessing advances from step 138 to step 143. In step 143, the zoomcode ZC after changing is tested to determine if it is equal to "1"while the zoom code before changing is equal to 5. If the comparison forthe two are affirmative, processing advances to step 144, where thecamera concludes that the lens has moved from a position code POS of"2_(H) " to a position code POS of "1_(H) ". As a result, the positioncode POS is forcibly set to "1_(H) ", and stored in memory, ZC FOW isset to "5" and ZC REV is set to "3". Thereafter, control returns to thepoint from which the subroutine was called.

Due to the above operation, if there is an error in the temporarily setposition code, it is corrected.

Returning to step 137, if it is determined that the zoom motor isrotating in the forward direction, the subroutine proceeds to step 145,where it is decided whether the zoom code ZC after the lens has moved isequal to the change estimation value ZC FOW. If they are the same, theposition code POS is increased by "1_(H) ", the zoom code is stored inmemory, and the change estimation codes ZC FOW and ZC REV are set (step146). For example, if the lens is moved to point where the position codePOS is equal to "4_(H) ", ZC FOW will be equal to "7" and ZC REV will beequal to "4". Then, the value of the indication prohibition flagF_(NODSP) is examined to determine if it has been set to 1. If this flaghas been set to a value of 0, the focal length of the lens is indicatedon the display panel (step 148). When the value of the prohibition flagis set to 1, step 148 is skipped. Regardless of whether the focal lengthof the lens is displayed or not, the code change flag F_(CHNG) is theset to 1 in step 149 before the subroutine returns to where it wascalled.

It is not always determined in step 136 that the zoom code stored inmemory is different from the zoom code inputted in step 134 when thelens zooms by the change caused by actually switching the zoom code, asmentioned above. Namely, it is supposed that even though the lens isactually in the position which has the same position code bit, whichshould be 0, is detected as 1 due to a brush not contacting the codeplate. This separation of the brush from the code plate can occur due toa camera vibration or the existence of dust on the code plate, to name afew causes. Thus, the zoom code input does not agree with the valuestored in memory. In this case, the zoom code ZC does not agree with thechange estimation value ZC REV and ZC FOW and the test performed in step143 generates a negative result.

Therefore, the zoom code input in step 134 is electrically OR'ed toreverse the logic of the zoom code stored in the memory. This reversedvalue is tested to determine if it is equal to "111_(binary) " (step150). Because an electrical OR'ing operation is performed for thereverse and positive logic of two codes detected in the position wherethe same POS values are obtained, the result always becomes equal to"111_(binary) ", even if a bit, which should be 0, is interpreted as a 1and the judgment in step 150 becomes affirmative.

For example, when the zoom code stored in memory is the normal value"001_(binary) " at the position where POS equals "7_(H) " and anincorrect code "011_(binary) " is detected because terminal ZC1, whichshould be conductive, becomes off, "111_(binary) " is obtained byelectrically OR'ing for the reverse logic of the value in memory"110_(binary) " and the code "011_(binary) ". This prevents an erroneousposition code POS reading when a brush terminal, that should be detectedas ON is detected as OFF.

According to the present invention, any change in the zoom code due tothe separation of a brush from the code plate is not considered asresulting in a change in the position code but, rather, is handled as anerroneous reading of the position code. The construction of a camerasystem as described herein makes it possible to produce a more accuratelens position detecting system while also preventing inaccurate exposureoperations.

When the zoom code becomes an abnormal value, due to a cause other thanthe above-mentioned described momentary brush terminal separationsituation, steps 151-153 are executed. In these steps, the POS flagF_(POS) is set to 0 in step 151, the focal length of the lens isindicated on the display panel and CPU register stack processing isperformed. Then, processing diverges to a series of instructions (shownin FIG. 19) to execute a BAD CHECK (BC LOOP) operation.

As an example, assume the camera has a memorized zoom code of"001_(binary) ". This yields a reverse code of "110_(binary) ". Further,assume a new code is inputted, having a value of "110_(binary) ".Electrically OR'ing the reverse code with the new inputted code producesa value "110_(binary) ". Because the electrical OR'ing operation did notequal "111_(binary) ", processing goes to the BAD CHECK LOOP (BC LOOP)Operation. Thus, when the position code equals "7_(H) ", but the dataindicates the lens is at the point where the position code POS equals"0_(H) ", processing diverges to the BAD CHECK LOOP (BC LOOP) Operation.

ZOOM REVERSE ROTATION (ZMREV) Subroutine

FIG. 14 illustrates the flowchart of the ZOOM MOTOR REVERSE ROTATIONsubroutine which is called in step 22 of the MAIN program. Thissubroutine pulls the lens into the lock position when the lock switchSWL is ON, when the lock switch is set to OFF in the zoom range duringan operation to pull in the lens, and the operation which returns thelens from the macro position to the zoom range when the macro switch isset to OFF. To stop the lens in the zoom range, a forward rotationoperation is included to remove any possible backlash.

When this subroutine is called, the focal length of the lens isindicated on the LDC panel as the lens is rotated in the reversedirection (steps 160 and 161). Thereafter, wide extremity flag F_(WIDE)is cleared and reset to 0.

The ZMREV subroutine calls the COD CHK subroutine to obtain the positioncode of the lens (step 163). The position code POS is then tested todetermine whether it is greater than or equal to 37 D_(H) ". Until theposition code is at least equal to "D_(H) ", processing loops betweensteps 163 and 164. When the position code becomes greater than or equalto "D_(H) ", the lens is in the zoom range or in the lock position andprocessing continues to step 165.

In step 165, the lock switch SWL is checked to determine if it is set toON. If this switch is ON, processing goes to the CODE CHK subroutinestep 166). The position code POS is then checked to determine if it isgreater than or equal to "2_(H) ". When the position code is greaterthan or equal to "2_(H) ", the lens is in the zoom range. Thus,processing loops between steps 165-167. When the position code POSbecomes smaller than "2_(H) ", the execution of the loop is terminatedand processing proceeds to step 168.

In step 168, the CODE CHK subroutine is recalled. Thereafter, theposition code POS is checked to determine if it is equal to "0_(H) ".Until the position code is "0_(H) ", a loop is executed between theoperation of executing the CODE CHK subroutine and testing the positioncode (steps 168 and 169). Once the position code is "0_(H) ", step 170is executed to apply a zoom motor brake to stop the movement of thelens. Control then returns to the MAIN program.

However, when the lock switch SWL is detected as being OFF in step 130of the CODE CHECK subroutine (that was called in step 166 of the presentsubroutine), while the lens is judged to be in the zoom range in step167, the position of the lock switch SWL in step 165 will be judged tobe OFF. Accordingly, processing will proceed to steps 171-178.

When the lock switch SWL is determined as being OFF in step 165, theindication prohibition flag F_(NODSP) is set to 1 (step 171). The CODECHK subroutine is then executed (step 172), after which the code changeflag F_(CHNG) tested (in step 173) to determine if it has been set to 1(in step 139 of the CODE CHECK subroutine). Until the code change flagis set to 1, processing loops through steps 172 and 173. After it isdetermined that the code change flag F_(CHNG) has been set to 1, thatis, the position code POS has been renewed, processing pauses for t₁ ms(step 173) before rotating the zoom motor in a forward direction in step175.

When the position code POS is renewed in the loop of steps 176 and 177,the indication prohibition flag F_(NODSP) is cleared in step 178. Thezoom motor brake is then applied (step 170) and control returns to thepoint from which this subroutine was called. The stop position of thelens in this operation has twelve steps, shown by circles in FIG. 26.

In the ZOOM MOTOR REVERSE subroutine, the zoom motor is stopped at thepoint where the position code POS is renewed by rotating the zoom motorforward after the motor has once passed the boundary section of aposition code POS. This cancels any possible backlash that may occur.For example, as shown in FIG. 26, when the lock switch SWL is changedfrom ON to OFF at the position where POS equals "7_(H) " and the focallength indication is not prohibited, the value "46 mm" is indicated onthe display panel. When the zoom motor causes the lens to enter the areawhere POS equals "6_(H) ", the display is changed to indicate "50 mm"when it enters the area of POS equals "7_(H) ". This may give a user theimpression that the camera is malfunctioning by switching to the telerange just before the stop operation, despite the fact that theoperation shifts the focal length of the lens to the wide extremity.Therefore, to prevent such a misconception, the indication prohibitionflag F_(NODSP) is set to 0 (step 178) so that the focal lengthindication of the lens is shown again at the point when the zoom motorstops rotating.

When this subroutine is called in step 22 of the MAIN program, the focallength indication is maintained on the display for a period of onesecond, in response to the indication counter SCANT being set to "8" instep 29.

ZOOM FORWARD ROTATION (ZMFOW) Subroutine

FIG. 15 shows the flowchart of the ZOOM MOTOR FORWARD ROTATIONsubroutine, which is called in step 26 of the MAIN program. Thissubroutine prescribes the operation that occurs when the lock switch SWLis changed from ON to OFF, the macro switch SWM is changed from OFF toON and then the macro switch SWM is set to OFF before the lens reachesthe macro extremity.

When the ZOOM MOTOR FORWARD ROTATION subroutine is called, the focallength of the lens is indicated on the LCD display. In addition, thewide extremity flag F_(WIDE) is cleared and set to 0, while the zoommotor starts to rotate the lens in a forward direction (steps 180-182).

The CODE CHECK subroutine is performed and a determination is made as towhether the position code POS is less than or equal to "1_(H) " (steps183 and 184). If the position code is equal to "0_(H) " or "1_(H) ", thelens is in a position between the wide extremity of the zoom range andthe lock position. To permit the motor in the forward rotation to passthe wide extremity or stop at the wide extremity, the wide extremityflag F_(WIDE) is set to 1 in step 185. Processing then loops back tostep 183.

The camera constructed according to the present invention is designed sothat backlash from the gear system is removed and the stop position ofthe lens in the wide extremity is set just after the position code POSswitches from "1_(H) " to "2_(H) ". For instance, the lens is not alwayspositioned at the wide extremity of the focal length (i.e., 38 mm) evenwhen the position code POS is set to "2_(H) ". It cannot always bedetermined if the lens is in the wide extremity by only examining theposition code POS. That is the reason for the setting of the wideextremity flag F_(WIDE).

If the position code POS becomes greater than "1_(H) ", according to themovement of the lens to the wide extremity, or the position code POS isalready greater than "1_(H) " at the time that this subroutine iscalled, the macro switch SWM is checked to determine if it has been setto ON (step 186).

When the macro switch SWM is ON, processing advances to step 187, sothat the lens is moved to the macro extremity where the position codePOS is "E_(H) ". When the value of the position code obtained from theCODE CHECK subroutine called in step 187 is determined to be less than"C_(H) " (step 188), that is, the lens is in the zoom range, processinggoes to step 190 to set the wide flag F_(WIDE) to 0, before looping backto step 186. Thus, as long as the position code is less than C_(H), aloop comprising steps 186-189 is formed.

At some point, the position code will be greater than or equal to "C_(H)". When this occurs, process breaks out of the loop and goes to step190, which repeats the CODE CHK subroutine (steps 190 and 191) until theposition code becomes equal to "E_(H) ". When this occurs, the zoommotor brake is applied (step 192) and processing returns to the pointjust after from which this subroutine was called.

When the macro switch SWM is determined to be OFF (in step 186), or itis set to OFF while the lens is in the zoom range, the wide extremityflag F_(WIDE) is tested (step 193) to determine its status.

As noted above, the wide extremity flag F_(WIDE) has been set to 1 instep 185 and processing advances to step 186 just after the positioncode POS switched from "1_(H) " to "2_(H) ", that is, the lens is in thewide extremity. In this case, the zoom motor is stopped in step 192, thelens being set to the wide extremity and the subroutine ends.

However, when the wide extremity flag F_(WIDE) is 0 in step 193,processing loops through steps 194 and 195 until the position code POSis switched in step 195 as detecting the result obtained from the CODECHECK subroutine called in step 194. When the position code POS changes,as indicated by the code change flag F_(CHNG) being set to 1, the zoommotor brake is applied in step 192 and the subroutine ends.

There are twelve stop positions performed by this subroutine for thelens which are marked by circles in FIG. 26.

For example, when the lens is in the lock position and the lock switchis set to OFF so as to call this subroutine, the stop position is set tothe point where the position code POS switches from "1_(H) " to "2_(H)", that is, the wide extremity. When the macro switch is changed from ONto OFF in the range of POS equals "7_(H) ", the lens stops at the pointwhere the position code POS switches from "7_(H) " to "8_(H) ".

ZOOM WIDE (WIDE) Subroutine

FIG. 16 illustrates the flowchart of the ZOOM WIDE subroutine that iscalled by setting the zoom wide switch SWW to ON when the lens is in thezoom mode and does not reach the wide extremity. The operations to shiftthe focal length of the lens to the wide extremity are similar to theoperations performed in the above-described ZOOM MOTOR REVERSE ROTATIONsubroutine. However, in the WIDE subroutine, the lens can stop at anydesired position in its travel range.

When the WIDE subroutine is invoked, the focal length of the lens isindicated on the LCD display panel (step 200) and the zoom motor iscaused to start rotating in the reverse direction (step 201).Thereafter, the CODE CHECK subroutine is executed and the status of thelock switch SWL, macro switch SWM, wide switch SWW and position code POSare checked, If either the lock switch SWL or the macro switch SWM is ON(steps 203 and 204), the zoom motor brake is applied and processingreturns to the MAIN program. When both switches are OFF, the positioncode POS is checked to determine if it is equal to "1_(H) " in step 206,which indicates that the lens is in a stop prohibition area between thelock position and the zoom range. If the lens is in the stop prohibitionarea, the zoom motor is rotated forward (step 208) after having pausedfor a period of t₁ ms, as shown in FIG. 26. The subroutine waits untilthe position code POS switches from a value of "1_(H) " to "2_(H) " insteps 209 and 210. When the position code changes, as indicated by thestatus of the code change flag F_(CHNG), the wide extremity flagF_(WIDE) is set to 1 (step 211), the zoom motor brake is applied (step212) and the subroutine ends. In this case, the lens is set to the wideextremity.

When the position code POS, tested in step 206, does not equal "1_(H) ",the status of the wide switch SWW is checked in step 213. If the wideswitch SWW is set to ON, processing loops back to step 202. Thus, inthis case, a loop is formed involving steps 202-213 until the lensreached the wide extremity.

When the wide switch is set to OFF, as determined in step 213, theindication prohibition flap F_(NODSP) is set to 1 (step 214) and a timeris started to count a period of t₂ ms (step 215). Then, the positioncode POS is obtained by executing the CODE CHK subroutine in step 216.If the time period has not reached t₂ ms (step 217), processing jumpsback to step 216. When the time period t₂ ms is reached, the zoom motoris started to rotate in the forward direction (step 218) to move thelens to the tele range. In step 219, the t₁ ms timer is restarted andthe CODE CHK subroutine is rerun. Then, the CODE CHK subroutine isexecuted and the timer is checked to see if the time period t₁ ms hasbeen reached. If the time period has not been reached, processing jumpsback to step 220 to re-execute the CODE CHK subroutine. When the timeperiod t₁ ms has been reached, processing advances to step 222.

The time periods for the two timers are selected such that t₁ is lessthan t₂, as shown in FIG. 26. The time period t₁ corresponds to the timethat is required to eliminate backlash of the mechanical system, whilethe time period t₂ corresponds to the an arbitrary value that is largerthan t₁. If the time period t₂ is shorter than t₁, the lens would stopat a point closer to the tele extremity than is desired.

In step 222, the indication prohibition flag F_(NODSP) is cleared andset to 0. The purpose of this flag setting was explained in the ZOOMMOTOR REVERSE ROTATION subroutine. Then, the focal length of the lens isdisplayed on the LCD display panel, the zoom motor brake is applied andthe subroutine returns to the MAIN program.

ZOOM TELE (TELE) Subroutine

FIG. 17 shows the flowchart of the TELE subroutine, which is called instep 38 of the MAIN program. This subroutine is called by setting thetele switch SWT to ON when the lens is in the zoom range and theposition code POS is not equal to "C_(H) ". The operation of activatingthe zoom motor so that it rotates in a forward direction to move thelens to the tele extremity is similar to the operation performed in theabove-described ZOOM MOTOR FORWARD ROTATION subroutine. It is the sameas the WIDE subroutine in that the lens can stop at any desired positionin its travel range.

When the TELE subroutine is called, the focal length of the lens isindicated on the LCD display panel and the zoom motor starts to rotatein a forward direction. The CODE CHK subroutine is called in step 232,and the status of the lock switch SWL, the macro switch SWM, the teleswitch SWT and the position code POS are checked. If either the lockswitch or the macro switch (steps 233 and 234) are ON, processingadvances to step 235, which applies the zoom motor brake and returns tothe point just after where the subroutine was called.

When the lock switch and the macro switch are both OFF, the positioncode POS is examined (in step 236) to determine whether it is greaterthan or equal to "C_(H) ". If the position code is less than "C_(H) ",the tele switch is checked to determine if it is still ON (step 237).When the position code POS is greater than or equal to "C_(H) ", thetest that is performed on the tele switch is skipped, because the lenshas reached the tele extremity. Thus, processing jumps to step 238, soas to apply the zoom motor brake and return to the MAIN program.

However, if the position code is less than "C_(H) ", meaning that thetele switch is OFF, processing loops back to step 232. The subroutinestays in the loop comprising steps 232-237 while the tele switch SWT isON, until the lens reaches the tele extremity. When the tele switch SWTis set to OFF (step 237), as shown in FIG. 26, the zoom motor brake isapplied (step 238) and control returns to the MAIN program.

BACKUP Operation

FIG. 18 illustrates the series of instructions that are executed toperform a BACKUP operation. This operation is performed by divergingfrom steps 6 and 57 of the MAIN program, as well as from an BAD CODELOOP (BC LOOP) operation and the RESET operation. These instructions areperformed to maintain data in the memory for a fixed period of time bypowering the main CPU with electrical current supplied from the backupcapacitor 320 when the battery 300 is removed or is depleted. When thecamera goes into the BACKUP operation, all functions that require alarge amount of electrical power are suspended so that the data in thememory can be retained for as long as possible.

When the BACKUP operation begins, all inputs with the exception of thelock switch SWL, macro switch SWM, battery switch SWB and film switchSWF are ignored in order to minimize electric power consumption. This isaccomplished by switching the ports on the CPU 100 from an input mode toan output mode by a PORT INITIALIZATION subroutine in step 250. Thus,only information for the above-noted four switches will be detected.

In step 251, an indication of the frame to which the film is advanced isdisplayed on the LCD display panel. Then, the clock rate of themicroprocessor is switched to a lower frequency. The operating speed ofthe camera is reduced so as to lower the power requirements of thecamera circuitry. As is generally known, the faster an electricalcomponent is operated, the more current that component usually requires.For instance, when a microprocessor is operated at a 6 MHz clock rate,the microprocessor may draw 200 uA of current. If that samemicroprocessor is operated with a 8 MHz clock rate, the microprocessorwill operate approximately 33 percent quicker than at the 6 MHz speed,but it may require 300 uA of current. Thus, one technique for reducingpower consumption of an electrical circuit is to reduce its clock rateand this is accomplished by running the PORT INITIALIZATION subroutine.

Next, a timer is started (step 253). This timer is used to erase thefilm frame indication on the display panel and also to determine thememory setting of several switches. In step 254, the battery switch SWBis tested to determine whether it is set to ON. If the switch is set toOFF, the film indication on the LCD display panel starts to blink whenthe battery is removed (step 255). The film switch SWF is then checkedin step 256 to determine if it is set to OFF. If this switch is ON,loading request flag F_(FDRQ) and loading end flag F_(LDEND) are clearedand set to 0 (step 257), the film frame indication on the display panelis erased (step 258) and processing proceeds to step 259.

If the film switch SWF is OFF, steps 257 and 258 are skipped, meaningthat the processing goes from step 256 to step 259. At step 259, thetimer is checked to determine whether a period of at least two minuteshas passed since the timer was started. If less than two minutes haspassed, processing jumps back to step 254. When the time period isgreater than or equal to two minutes, processing goes to step 260,wherein it is determined if the timer flag F_(TM) is set to 1.

The timer flag F_(TM) is initially set to 0. When step 259 indicatesthat at least two minutes has passed since the timer was started,processing goes from step 259 to step 260. However, at this time, thetimer flag will be equal to 0. Thus, step 261 is executed, which forcesthe timer flag F_(TM) to be set to 1. In step 262, the LCD display panelis deactivated to conserve additional electrical power. Then, processingjumps back to step 254. The BACKUP operation stays in the loop of steps254-260 until the battery switch SWB is set to ON.

If the timer test in step 259 indicates that less than two minutes haspassed since the timer was started, steps 261 and 262 are skipped. Thus,when electrical power to the camera is removed, the LCD display panelwill continue to indicate a display for a period of two minutes. Afterthe two minute period, the display panel will be shut off.

When a battery is installed in the camera, as indicated by the batteryswitch being ON in step 254, processing comes out of the above-mentionedloop, the clock rate is switched back to its normal rate (step 263) andit is determined whether a time period of seventeen or more minutes havepassed since the timer was set in step 264.

If less than seventeen minutes have passed, the timer flag F_(TM) isexamined to determine whether it is set to 1 (step 265). If the flag isset to 1, power for the LCD display panel (which was turned OFF in step262) is reapplied (step 266) and the timer flag F_(TM) is cleared andset to 0 in step 267. Thereafter, backup flag F_(BC) is set to 1 in step268 and processing diverges to the BAD CODE LOOP (BC LOOP) operation toperform error processing.

When the timer flag F_(TM) is set to 0, steps 266 and 267 are skipped.Consequently, the LCD display panel is not reactivated. Instead,processing goes from step 265 to step 268.

When it is determined that more than seventeen minutes have passed sincethe timer was started, the timer flag F_(TM) is cleared and set to 0 instep 269 and processing diverges to the series of instructions thatperform the RESET operation.

BAD CODE LOOP (BC LOOP) Operation

FIG. 19 shows the flow of the series of instructions that perform errorprocessing. These instructions are executed by diverging from the CODECHECK subroutine or the BACKUP operation.

When the BC LOOP starts, data for the lock switch SWL and macro switchSWM are inputted and stored in memory (step 280). Then, the back up flagF_(BC) is tested to determine whether it is set to 1. That is, adetermination is made as to whether the error operation is divergingfrom the BACKUP operation (step 281). When the backup flag is set to 1,it is reset at 0 in step 282. Afterward, the LCD display panel isswitched to OFF (step 283) and processing diverges back to the MAINprogram.

When the BC LOOP is executed after the CODE CHECK subroutine, the testperformed in step 281 will be negative. Thus step 284 is processed, inwhich switch data is inputted. Based upon this input, the battery switchSWB is tested to determine if it is ON. When the battery is removed,processing goes to step 286, wherein the LCD display panel is shut downand processing advances to the BACKUP operation.

When the battery switch is determined to be ON, the tele switch SWT,wide switch SWW and photometry switch SWS are examined (step 287). If atleast one of these switches is set to ON, processing advances to step289.

Alternatively, if all three switches are off, step 288 is checked todetermine whether the setting of lock and macro switches (SWL and SWM)are different from their values stored in the memory. If these switchsettings differs from what was stored in the memory, processing advancesto step 289.

In step 289, the voltage of the battery is checked. If the batteryvoltage is more than a predetermined value, the battery is considered asbeing good. Thus, the blinking of the LCD display panel becomes OFF step283) prior to diverging to the MAIN program. The MAIN program will thendetermine what information should be displayed on the LCD display panel.

When (1) the tele switch SWT, wide switch SWW and photometry switch SWSare all OFF and the setting of the lock switch SWL and macro switch SWMare the same as the values stored in the memory for the respectiveswitches (steps 287 and 288), or (2) the battery is judged as being nogood (step 289), the LCD display panel blinks ON in step 290. Thesetting of the lock switch SWL and macro switch SWM are stored in memory(step 291) and a 500 ms pause is introduced (step 292) prior to the BCLOOP jumping back to step 284, so as to loop through steps 284-292 untila good battery is placed in the camera.

RESET Operation

FIG. 20 illustrates the series of instructions that are executed whenthe RESET operation is performed. This operation is executed at the timeof a reset-start or when processing diverges from the BACKUP operation.The RESET operation diverges from the BACKUP operation when more thanseventeen minutes have passed since a battery was removed from thecamera or a battery in the camera fails. The RESET operation isperformed because the capacitor 330 is only intended to retain thecontents of the memory for approximately seventeen minutes. Afterseventeen minutes, the data stored in the memory may be inaccurate ormay not be reliably read back.

First, all memory locations and flags are cleared in step 300. Thus, theposition code flag F_(POS) is also cleared so that the POSITION CODEINITIALIZATION subroutine is called when the MAIN program starts.Thereafter, power is applied to the LCD display panel and the PORTINITIALIZATION subroutine (discussed above) is called (steps 302 and303). This subroutine sets all ports on the CPU 100 (except for the lockswitch SWL, macro switch SWM, battery switch SWB and film switch SWF) tothe output mode.

The status of the film switch SWF is inputted in step 305, after checkedin step 308 to determine whether it is OFF. If the film switch is OFF,film loading becomes possible. Therefore, the film load request flagF_(LDRQ) is set to 1 in step 309 and the RESET operation diverges to theBACKUP operation.

However, if the film switch is set to ON, the film load flag F_(LDRQ) isnot set. That is, step 309 is skipped when the film switch SWF is OFF.Thereafter, processing diverges to the BACKUP operation.

FILM INDICATION Operation

The series of instructions to perform the FILM INDICATION operation areshown in FIG. 21. These instructions are executed by diverging from theMAIN program, the BACKUP operation, the LOAD operation and the LOCKoperation.

At step 320, flag F_(LDRQ) is examined to determine whether the registerhas been set to 1. Flag F_(LDRQ) is set to 1 when the back cover of thecamera is brought from an open position to a closed position, the filmis not completely loaded and the film loading indicator has not beenrequested. When it has been set to 1, a film load request pattern L_(d)is created, in response to the loading request in display memory XA, anddisplayed on the liquid crystal display panel of the camera (steps 322and 324), the flow operation is completed and control returns to thepoint just after where the FILM INDICATION operation diverged from.

However, if the film load indication flag F_(LDRQ) is set to 0,processing advances to step 326, where the film load end flag F_(LDEND)is checked. If the flag is set to 1, a FILM PATTERN ON subroutine (step329) is called. This subroutine performs a film count F_(c) check. WhenF_(c) is not equal to "0", step 332 is executed to display on the LCDdisplay panel the number of pictures that have been taken and store thecontent of the film counter F_(c) in display memory XA, before returningto the point from which this operation diverged.

If F_(LDRQ) equals 0 (in step 320) and F_(LDEND) equals 0 (in step 326),processing goes to step 334 to call a FILM PATTERN OFF subroutine.Information corresponding to the FILM PATTERN OFF is stored in thedisplay memory XA (step 336) and the LCD display panel is turned off.The FILM INDICATION operation then returns to where it diverged from.

If the film count F_(c) check in step 330 is equal to "0", processingproceeds to step 336, which was described above, and then returns to thepoint from which the operation diverged.

LOAD Operation and WIND PULSE CHANGE Subroutine

The following discussion is directed to the LOAD operation and WINDPULSE CHANGE subroutine, which are interrelated. The flowchart diagramfor the series of instructions that comprise the LOAD operation isillustrated in FIG. 22. This operation automatically winds the film thata user inserts into the camera to the correct location so as to permitthe taking of a photograph. The operation is performed when there is achange in the setting of the lock switch SWL, the macro switch SWM andwhen the release switch is set from OFF to ON, assuming that the loadingrequest flag F_(LDRQ) has been set to 1 in the MAIN program.

First, a wind pulse counter WPCNT is set to "18" in step 338. This countcorresponds to the winding of four and one-half frames of the film. AWIND PULSE CHANGE subroutine (step 340) then takes place in accordancewith the WIND PULSE CHANGE subroutine, a film advance (wind-up) motorstarts a forward rotation in step 3401. Initialization flag F_(WPINT)and wind pulse off flag F_(WPOFF) are then set to 1 in step 3402.

In step 3403, a 1.5-second timer is set and started. The 1.5second-timer is used to examine whether or not the film should berewound. If it is determined that the wind pulse counter WPCNT is notequal to "0" in the WIND PULSE CHANGE subroutine (FIG. 23), to bedescribed below, a return flag is set in step 3404, so that the forwardrotation of the wind-up motor is brought to a stop in step 3405, even if1.5 seconds or more have elapsed after the forward rotation of thewind-up motor or the increase in the wind pulse. Processing then returnsto the LOAD operation. This example is for the initial film loadingstage, in which the film normally advances with 1.5 seconds before theprocessing goes to step 3406. After switch data is inputted at step3406, step 3407 examines whether a battery is in the camera. This testis made to determine whether the battery was removed during theadvancing of the film. In such a case, processing diverges to the BACKUPoperation after the forward rotation of the wind-up motor is brought toa stop in step 3408.

With a battery loaded in the camera, step 3409 is executed. This stepchecks to determine if the film switch SWF is OFF or ON. If the filmswitch SWF is ON, step 3410 is processed. This step sets flags F_(LDRQ),F_(LDEND) and film counter F_(c) to "0", stops the forward rotation ofthe wind-up motor (step 3412) and then returns to the MAIN program. Thisoperation is performed in case the back cover of the camera is openedduring the film loading process (this process is known as a blank-shotfilm advancing operation).

If the back cover of the camera is kept closed, the film switch SWFremains OFF. Therefore, processing goes to step 3413, which determinesif the wind pulse off flag (F_(WPOFF)) equals 1. Since flag F_(WPOFF) isinitially 1, an affirmative answer is given to go to step 3414 todetermine whether SWWP equals 0. SWWP equalling 0 corresponds to a lowwind pulse W_(P) level. If the wind pulse W_(P) is not at a low level,processing returns to step 3404 to repeat the loop (comprising steps3404, 3406, 3407, 3409, 3413 and 3414) until the wind pulse W_(P)becomes low. Thereafter, the wind pulse W_(P) is switched from a highlevel to a low level and step 3415 is executed to set the flag F_(WPOFF)to 0. Processing then returns to step 3404, eventually returning to step3413. Since flag F_(WPOFF) will now be equal to 0, step 3416 will beexecuted to determine whether the flag F_(WPINT) and SWWP have changed.Because flag F_(WPINT) has been established in step 3402 to equal 1 andSWWP has been changed from 1 to 0, an affirmative answer is given to thetest in step 3416. Thus, processing goes to step 3417. Since the flagF_(WPINT) equals 1 in step 3417, processing goes to step 3418, where theflag F_(WPINT) is set to 0. After the flag F_(WPINT) has been set, thesubroutine executes step 3419 to examine whether SWWP equals 1. If thewind pulse remains low, a negative result is obtained. Therefore, step3404 is executed. Thus, processing loops through steps 3404, 3406, 3407,3413 and 3416. When the flag F_(WPINT) has been changed from 1 to 0 (instep 3416), SWWP remains equal to 0 so that processing goes back to3404. In the meantime, the wind pulse W_(P) is switched from a low levelto a high level. This means that a change has taken place both in theflag F_(WPINT) and SWWP in step 3416. Therefore, step 3417 is processed.Since flag F_(WPINT) equals 0 in step 3417, processing goes to step3420, wherein flag F_(WPINT) is set to 1. Then, step 3419 is executed,wherein the wind pulse is switched from a low level to a high level andSWWP is set to 1 so that a FILM PATTERN BLINK INDICATION subroutine isperformed in step 3421. The FILM PATTERN BLINK INDICATION subroutineilluminates the film pattern in the LCD display panel when the windpulse is switched from a low level to a high level. This causes theliquid crystal display panel to show a display that corresponds to theactual advancing of the blank-shot film. After executing the subroutinein step 3421, "1" is subtracted from the wind pulse counter WPCNT (step3422), so that the content of wind pulse counter WPCNT becomes equal to"17". Step 3423 then examines whether the wind pulse counter WPCNTequals "0". If the wind pulse counter WPCNT is not equal to "0", theWIND PULSE CHANGE subroutine returns to step 3403, where the processingmentioned earlier is repeated. That is, in the WIND PULSE CHANGEsubroutine, the content of the wind pulse counter WPCNT is subtractedone by one upon every rise of the wind pulse W_(p). When the wind pulsecounter WPCNT reaches "0", the forward rotation of the film advancemotor is stopped (step 3424), a flag is set for the non-execution of aREWIND operation and the processing goes to step 342 of the LOADINGoperation.

Step 342 determines whether the REWIND subroutine should be performed.When step 3423 of the WIND PULSE CHANGE subroutine is executed, anegative answer is given regarding whether to proceed to step 344, whileif processing goes through step 3404, an affirmative answer is given togo to steps 346 and 348. In steps 346 and 348, F_(LDEND) is set to 1 andF_(LDRQ) is set to 0 for the REWIND operation. In steps 344, 350 and352, the film counter F_(c) is set to "1", F_(LDEND) is set to 1 andF_(LDRQ) is set to 0. Then, the FILM INDICATION operation (step 354),which was previously described, is performed.

REWIND Operation

FIG. 24 illustrates the flowchart of the REWIND operation which divergesfrom step 62 of the MAIN program and from the above-mentioned LOADINGoperation. This operation rewinds the film back into the patron when thelast film frame has been exposed.

In step 360, the wind-up motor is started in a reverse rotationdirection. Thereafter, step 362 is performed to determine whether thefilm loading detector switch SWF is off. This step functions to detectthe stopping of the wind-up motor. When SWF is on, processing advancesto step 364 to stop the reverse rotation of the wind-up motor, setF_(c), F_(LDRQ) and F_(LDEND) to 0, and turn off the film caseindication and film pattern that are shown on the LCD display panel.Then, the subroutine returns to the beginning of the MAIN program. IfF_(LDRQ) and F_(LDEND) equal 0, processing goes to the MAIN program andruns until it reaches the FILM INDICATION subroutine. Now, sinceF_(LDRWQ) equals 0 and F_(LDEND) equals 0, step 320 (of the FILMINDICATION subroutine) gives a negative answer and step 326 gives anaffirmative answer. In step 334, a FILM PATTERN OFF subroutine isexecuted, and information corresponding to the film pattern off isstored in the display memory XA (step 336), with the film indicationarea on the liquid crystal panel turned blank.

When the film switch SWF (in the REWIND operation) is off, processinggoes to step 366, where a wind pulse detection operation is performed.This step detects the change to the wind pulse from a low level to ahigh level. Then, in step 368, a film pattern blink indication operationis executed. In the film pattern indication operation, the film patternshown on the LDC display panel is turned-off at the time the wind pulsechanges from a low level to a high level. Then, in step 370, adetermination is made as to whether four wind pulse changes from low tohigh have occurred, indicating that one frame of the film has beenrewound.

If step 370 indicates that one film frame has not been rewound, steps362-370 are repeated. Thus, an indication corresponding to the filmbeing rewound appears on the LCD display panel. If one frame of the filmhas been rewound (as indicated by the test performed in step 370), step372 is performed.

In step 372, the content of the film counter F_(c) is decreased by "1".Thereafter, the FILM INDICATION subroutine is called (in step 374) toindicate the frame number of the film on the LDC display panel. When thefilm INDICATION subroutine is completed, the REWIND operation jumps tostep 362, looping through its instructions until SWF is turned ON.

LOCK Operation

FIG. 25 illustrates the flowchart of the LOCK operation which divergesfrom step 21 of the MAIN flow. This processing diverges when the lockswitch is set to ON and the photographing lens is stored in the lockposition.

In step 380, the port initializing operation is performed and the modeof the ports on the CPU 100 is switched from the input mode to theoutput mode, so as to conserve battery power, as was previouslyexplained. Then step 380A is executed to erase the mode indication andbattery indication from the LCD display panel 32.

In step 381, the loading request flat F_(LDRQ) checked to determine ifit is set to 1. If this flag is set to 0, the loading end flag F_(LDEND)is checked to determine if it is set to 1 in step 382. If both testresults are negative, power to the LCD panel is removed. When either theloading end flag F_(LDEND) or the loading request flag F_(LDRQ) are setto 1, the FILM INDICATION subroutine of step 384 is called.

In step 385, data for the lock switch SWL, battery switch SWB and filmswitch SWF are inputted and examined to determine if the data that wasinputted have changed from the data that is stored in memory (step 386).When there is no change, processing goes to step 387, looping throughsteps 385-387 (with a pause of 125 ms in step 347) until there is achange between the settings in memory and the actual switch settings.When there is a change, power is reapplied to the LCD panel in step 388.

Based upon the switch data input from step 389, step 390 determines ifthe battery switch SWB is ON. If this switch is OFF, processing divergesto the above-mentioned BACKUP operation (step 391), while if it is ON,the condition of the lock switch SWL is checked (step 392).

If the lock switch is OFF, processing of the LOCK operation does nothave to continue. Thus, step 392A is performed. This step switches themode indication and the battery indication on the LCD display 32 to ON.Then, step 393 is performed to determine if there is a request forloading of the film. If there is a request, processing diverges to theLOAD operation (step 394), which was previously described. If step 393indicates that there has been no request to load film, processingdiverges back to the MAIN program.

If step 392 indicates that the lock switch SWL is set to ON, processinggoes to steps 395 and 396. Step 395 tests whether F_(LDEND) is equal to1, while step 396 tests whether F_(LDRQ) is equal to 1. If the testsperformed in either step 395 or step 396 is affirmative, a test is made(in step 399) to determine whether the film load detector switch SWF isset to OFF. However, if steps 395 and 396 are both negative, processingproceeds to step 397.

Steps 397 and 399 check whether the film loading detector switch SWF hasbeen turned off. If the film loading detector switch SWF is determinedto be OFF in step 397, processing goes to step 398, wherein F_(LDRQ) isset to be equal to 1. Thereafter, the FILM INDICATION subroutine (step402) is called. If the test performed in step 397 is negative or thetest of step 399 is positive, processing goes to step 403. If step 399results in a negative answer, F_(LDEND) and F_(LDRQ) are each set to 0(steps 400 and 401) and the FILM INDICATION subroutine of step 402 iscalled. Thereafter, processing continues to step 403, where a check ofF_(LDRQ) is made.

In step 403 and step 404, if it is judged that both the loading requestflag F_(LDRQ) and the loading end flag F_(LDEND) are set to 0, power tothe LCD display panel is removed in step 405.

In step 406, the switch data that were inputted in step 389 are storedin memory and the processing advances to step 387. If one of theabove-mentioned flags is set to 1, step 405 is skipped. Thus, electricalpower continues to be supplied to the LCD display panel.

Thus, in the LOCK operation, when the status of the lock switch SWL,battery switch SWB and film switch SWF does not change, processing staysin the loop of steps 386-387. When there is a change in the status ofthe film switch SWF, only one cycle of the loop of steps 388-406 isperformed. When the status of the lock switch SWL and the battery switchSWB change, processing exits these loops to advance to the next step inthe routine.

DATA I/O Operation and MACRO TELE SHIFT (MT SIFT) Subroutine

Before describing the DATA I/O subroutine, illustrated in FIG. 27B, adescription of the relationship of the distance measurement step, lenslatch and focus position will be given. Reference for this discussion ismade to FIG. 28.

Distance measurement steps are represented in increments from 1 to 36.As indicated in FIG. 28, the distances for these steps are listed on theright side of the distance measurement steps. For example, distancemeasurement step "1" corresponds to 5 m-∞ and distance measurement step"2" corresponds to 3.7-5 m. Also, as indicated in FIG. 28, in the zoommode, lens latch steps are represented in steps of "1" and "3" to "19",corresponding to the distance measurement steps from "1" to "18" of thezoom lens 11. For example, for a distance measurement step of "1", theideal focus position for a lens latch step of "1" is 9 m. The latch stepof "1" allows one to take a photograph in an in-focus condition from arange of 5 m-∞. For a distance measurement step of "2" , correspondingto a latch step of "3", the ideal focus position is 4 m. At latch step"3", a photograph can be taken at an in-focus condition having a rangeof 3.7 m-5 m.

The electronically controlled camera of the preferred embodiment isunable to take an in-focus photograph of a subject for distancemeasurement steps of "19" to "36" when the camera is in the zoom mode.In this situation, a release lock or short distance warning (to bementioned below) is shown in the LCD panel 32. The user then switchesfrom the zoom position SWZ to the macro position SWM, by manuallyoperating the main switch 30, so that the camera is switched from thezoom mode to the macro mode.

In the macro mode, lens latch steps are set from "1" to "19", whichcorresponds to distance-measuring steps "16"-"36". As shown in FIG. 28,distance measurement steps "16" and "17" correspond to lens latch step"1" in the macro mode. The ideal focus position of macro lens latch step"1" is 0.96 m. Macro lens latch step "1" allows one to take an in-focusphotograph in the range of 0.94 m to 1 m. Distance measurement step "18"corresponds to macro lens latch step "2". The ideal focus position formacro lens latch step "2" is the same as that for lens latch step "19"in the zoom mode. This permits one to take an in-focus photograph in therange of 0.9 m to 0.94 m.

Distance measurement steps "16" to "18" overlap, as shown in FIG. 28, sothat in-focus photographing is possible in both the zoom and macro modesat those steps. That is, the long distance side of the macro mode andthe short distance side of the zoom mode are overlapped in the rangefrom the boundary on the long distance side in the focus range in themacro mode (1 m) to the boundary on the short distance side in the focusrange in the zoom mode (0.9 m). This avoids a situation whereinphotographing cannot be performed in the macro mode because offluctuations in distance measurements when photographing by manuallyoperating the main switch 30 to switch to the macro mode in response toa warning that the taking of an in-focus photograph is impossible in thezoom mode.

In the preferred embodiment of the camera of the present invention,distance measurement step "36" corresponds to lens latch step "19" ofthe macro mode. In this case, only the short distance warning is givenand the release lock is not performed.

In the macro mode, distance measurements from "1" to "15" correspond tolens latch steps "1" and "3"-"16", performing a MACRO-TELE SHIFTsubroutine (MT SIFT subroutine), to be discussed below. For example, inthe macro mode, when a distance measurement of "1" is obtained, the zoomlens 11 is operated to shift the lens from the macro extremity to thetele extremity in the zoom range to correspond to lens latch step "1".The ideal focal length of lens latch step "1" is 9 m; a lens latch valueof "1" permits an in-focus picture to be taken within a range of 5 m-∞.

A description of the MACRO-TELE SHIFT Subroutine (MT SIFT), will now begiven, together with an explanation of the DATA I/O operation. Referenceis made to FIGS. 27B and 29 for this discussion.

The first step performed in the DATA I/O subroutine (step 420), is theconversion of the DX code of the film loaded in the camera to an ISO SVsensitivity value. At step 422, the zoom code POS information of thezoom lens 11 is alpha-converted to yield an exposure operation for usein step 424. The resultant alpha value comprises an amount of variationin F_(min) (full-open aperture F-number) of the zoom lens positioned atthe specified focal length position, with respect to the F_(min) of thezoom lens positioned at the wide extremity. At step 424, an exposureoperation flag is set. In response to the completion of step 424, step426 is executed to input distance measurement data from the CPU. Then,at step 428, a LENS LATCH (LL) subroutine is called.

After the LENS LATCH (LL) subroutine (see FIG. 30) is completed, step430 of the DATA I/O subroutine of FIG. 27B is performed. In this step,photometry data information is input. Then, in step 432, an AUTOEXPOSURE CALCULATION AND FLASHMATIC CALCULATION (AEFM) subroutine iscalled. When the AEFM subroutine is completed, a test is performed todetermine if the release lock flag R_(LOCK) is set to 1 (step 434). Ifthe result of the test is YES, processing diverges to a RELEASE LOCKPROCESSING operation, at step 435, to be described below.

If the result of the release lock flag test of step 434 is negative,step 436 is performed to determine whether the macro tele shift flag MTSIFT is equal to a value of 1. If MT SIFT equals 1, a macro tele shiftprocessing MT SIFT subroutine is performed (step 438). This subroutine,illustrated in FIG. 29, starts a reverse rotation of the zoom motor 10at step 4381. This permits the zoom lens to move towards the teleextremity. After this step has been completed, the position code POS ischecked at step 4382 and, based upon the obtained code, a test is madeat step 4383, as to whether the zoom lens is in the position where theposition code POS equals "B_(H) ". A loop between steps 4382 and 4383occurs until the zoom lens is positioned such that the position code POSequals "B_(H) ". When the zoom lens reaches the position where POSequals "B_(H) ", the reverse rotation of the zoom motor 10 is stoppedand a normal forward rotation of the zoom motor begins (step 4384).After step 4384 has executed, the position code POS is checked (step4386) to determine if the zoom lens is at the point where the code isequal to "C_(H) ". A loop between steps 4385 and 4386 occurs until theposition code POS equals C_(H). When the zoom lens is set to thespecified position of the tele extremity, a zoom motor brake (step 4387)is applied to stop the rotation of the zoom motor. This completes theMACRO TELE SHIFT (MT SIFT) subroutine. Processing control then returnsto step 440 of the DATA I/O operation.

To summarize, the MACRO TELE SHIFT (MT SIFT) subroutine of FIG. 29functions as a switching method for changing the zoom lens 11 from themacro extremity to the tele extremity when the distance measurementinformation indicates an unusable range in the macro mode.

After the main CPU executes the MACRO TELE SHIFT (MT SIFT) subroutine,if performs steps 440 and 442, so as to produce lens latch data (LLdata) and exposure data (AE data). These two steps are also performed ifthe result from the test in step 436 is negative (i.e., MT SIFT flagdoes not equal 1).

At step 444, a test is performed to determine whether the release switchSWR is set to on. If the release switch SWR is OFF, a test (in step 446)is made as to whether the photometry switch SWS is set to on. If thephotometry switch SWS is ON, step 448 is executed to decide if the lockswitch SWL is ON. If the lock switch SWL is OFF, the DATA I/O operationloops back to step 444, creating a release standby mode. That is, if therelease switch SWR is OFF, the photometry switch SWS is off and the zoomswitch SWZ or the macro switch SWM is ON, a release standby mode exitswherein steps 444 to 448 are constantly performed.

If the result of the test in step 446 indicates that the photometryswitch SWS is set to OFF, or the result of the test in step 448indicates that the lock switch SWL is ON, the DATA I/O operationdiverges back to the start of the MAIN program.

If the test made in step 444 indicates that the release switch SWR isset to ON, step 450, wherein the computer program diverges to a RELEASESEQUENCE operation, illustrated in FIG. 32 and discussed below.

LENS LATCH (LL) Subroutine

In the LL subroutine, shown in FIG. 30, distance measurement information(AF data) is converted to a distance measurement step (AF step) in step4281. The distance measurement step is restricted to a minimum valueAF_(min) of 1 and a maximum value AF_(max) of 36. Thereafter, step 4282is performed, wherein a determination is made as to whether the macroswitch SWM is turned ON. When the macro switch SWM is not ON, the LLsubroutine concludes that zoom switch SWM is ON and performs step 4283.In step 4283, the subroutine decides if the distance measurement step isless than or equal to "18". If an affirmative answer is obtained, aninfocus photograph can be taken in the zoom mode. Accordingly, step 4284is executed to perform the necessary processing to provisionally set thedistance measurement step value as the lens latch step LL. The softwareroutine then continues to step 4285, where a determination is made as towhether the lens latch step LL is less than or equal to "1". When LL isless than or equal to " 1", the LL subroutine is terminated andprocessing returns to the DATA I/O flow operation. When LL is greaterthan "1", the lens latch step LL is increased by "1" (in step 4286). Theprocessing returns to the DATA I/O operation. Therefore, for example,when the distance measurement step equals "2", a lens latch step of "3"is set. As previously discussed and shown in FIG. 28, each distancemeasurement step "1 to 18" corresponds to a respective lens latch stepof "1, 3 to 19".

When the distance measurement step (AF step) is equal to or greater than"19" in step 4283, step 4287 is executed so as to set a macro mark blinkflag 2MCMFL to 1, which causes a macro mark that is displayed on the LCDdisplay panel to blink. In addition, a release lock flag R_(LOCK) is setto 1. Step 4287 is performed because when the distance measurement stepis in the range of "19 to 36" while the camera is in the zoom mode, itis impossible to taken an in-focus picture. Thus, it is necessary tomake the macro mark blink as a warning aid to the user of the camera toturn ON the macro switch SWM, and set the release lock, so as to preventthe taking of an out-of-focus photograph. The LL subroutine thenproceeds to step 4293, which will discussed below.

When the macro switch SWM is ON in step 4282, the LL subroutine proceedsto step 4288, to determine whether the distance measurement step isgreater than or equal to "16". If it is determined that it is greaterthan or equal to "16", step 4289 is performed, wherein "16" issubtracted from the distance measurement step. Then, step 4290 isperformed, wherein the minimum value of lens latch step LL_(min) is setto "1". This step prevents LL_(min) from being set to "0" when a lenslatch step corresponding to a distance measurement step of "16" occurs.

After executing step 4290, the software subroutine proceeds to step 4291to decide whether LL is greater than or equal to "19". If LL is greaterthan or equal to "19", LL is set equal to "19" in step 4293. Inaddition, a green lamp flag GLAMPFL is set to 1 so as to cause the greenlamp Gd, located on the back of the camera body 1, to blink. Theblinking green lamp alerts the photographer that the subject is tooclose to the camera for a satisfactory picture. The LL subroutine isthen completed and processing returns to the DATA I/O operation. In themacro mode, processing to set the flag for the release lock is notperformed so that photographing is possible, even if a subject is tooclose.

If the distance measurement step is less than "16" in step 4288, step4292 is performed to set macro tele shift flag MT SIFT to 1. Then, steps4284 to 4286 are performed in the manner described above for thesesteps. That is, the distance measurement step is provisionally set tothe lens latch step LL and a test is made at step 4285 to determine ifLL is less than or equal to "1". If LL is less than or equal to "1", theLL subroutine is terminated and processing returns to the DATA I/Osubroutine. When the lens latch step LL is greater than "1", LL isincremented by "1" at step 4286, the LL operation subroutine isterminated, and processing of the DATA I/O operation continues.Therefore, for example, when the distance measurement step equals "2", alens latch step of "3" is set. Thus, lens latch steps from "1" and"3"-"16" will correspond to each value of the distance measurement step"1-15", as shown in FIG. 28.

RELEASE LOCK PROCESSING Subroutine

The RELEASE LOCK PROCESSING subroutine is illustrated in FIG. 31. Inthis subroutine, a determination is made as to whether the batteryswitch SWB is on (step 4351), and if it is, step 4532 is executed todetermine whether the photometry switch SWS is on. An affirmativedetermination results in a test being made (at step 4353) as to whetherthe lock position SWL is ON. If the lock position SWL is OFF, thesubroutine loops back to step 4531. Therefore, if the battery switch SWBis ON, the photometry switch SWS is ON and the lock switch SWL is OFF,the RELEASE LOCK PROCESSING subroutine performs a continuous loopbetween steps 4351 and 4353, until one of these three conditionschanges. That is, the loop is terminated by either setting the batteryswitch SWB to OFF, setting the photometry switch to OFF, or by settingthe lock switch SWL to ON.

When the battery switch SWB is turned OFF, processing diverges to theBACKUP operation, shown in FIG. 18 and discussed above. When thephotometry switch SWS is set to OFF, or the lock switch is set to ON,processing returns to the MAIN program.

RELEASE SEQUENCE Operation

FIG. 32 illustrates the set of instructions that comprise the RELEASESEQUENCE OPERATION. This operation diverges from step 450 of the DATAI/O operation, discussed above.

In the RELEASE SEQUENCE Operation, an exposure control is obtained instep 4501, which includes activating the shutter of the camera. Step4502 is then executed to determine whether the macro tele shift flag MTSIFT is set to 1. If MT SIFT equals 1, step 4503 is executed to decideif the macro switch SWM is ON.

If the macro switch SWM is ON, step 4504 is performed, which executes aTELE MACRO SHIFT (TM SHIFT) subroutine. The TM SIFT subroutine is thereverse of the MT SIFT subroutine explained in connection with FIGS. 27Band 29; hence, a further explanation of the specific operation of the TMSIFT subroutine is not given. When the macro switch SWM is ON, the TMSIFT subroutine operates to return the zoom lens 11 to the macroposition, after a photograph has been taken in the zoom position. Whenthe TELE MACRO SHIFT subroutine TM SIFT is completed, processingdiverges to a WIND operation (step 4505), to advance the film. The WINDoperation is shown in FIG. 32 and is discussed below.

If the macro tele shift flag MT SIFT test that was performed in step4502 is not equal to 1, the test for determining whether the macroswitch SWM is ON (step 4503) and the TM SIFT subroutine (step 4504) arenot performed. Rather, the RELEASE SEQUENCE operation jumps to step 4505to diverge to the WIND operation.

WIND Operation

The WIND operation is shown in FIG. 33. In the WIND operation, the windpulse counter WPCNT is set to be equal to "4" (step 45051). A count of"4" corresponds to one film frame in the preferred embodiment of theinvention. In step 45052, a check is made to see if F_(LDEND) is equalto 1. Since loading is not finished when F_(LDEND) equals 0, processingexits the WIND operation and returns to the start of the MAIN program.If F_(LDEND) equals 1, the FILM INDICATION subroutine, shown in FIG. 21is called. The number of pictures taken before the winding operation isindicated (step 45053), and the WIND PULSE CHANGE subroutine (shown inFIG. 11) is called in step 45054. After the execution of the WIND PULSECHANGE subroutine to advance the film by one frame, a determination ismade at step 45055 as to whether a REWIND operation should take place.If the determination is affirmative, processing diverges to the REWINDoperation shown in FIG. 24. If no rewind operation is to be performed,processing goes to step 45056 where the film counter F_(c) is increasedby "1". Processing then returns to the start of the MAIN program. Thus,the LCD display panel increments its display by one, showing thatanother picture has been taken (i.e., the display changes, for instance,from showing the number "1" to showing the number "2").

Operation of the Strobe Unit

The operation of the strobe unit will be explained with reference toFIGS. 34-37. FIG. 34 represents the MAIN program of the cameraconstructed according to the present invention, as depicted in FIGS. 9and 10 above. FIG. 34 has been condensed so as to emphasize theinstructions that are related to the operation of the strobe 22.Instruction steps that correspond to instructions illustrated in theflowchart of FIGS. 9 and 10 have been assigned the same step number inFIG. 34 to more easily explain how the steps pertaining to the operationof the strobe are interfaced with the MAIN program shown in FIGS. 9 and10. However, it is to be understood that the camera constructedaccording to the present invention has only one MAIN program whichcontains all the relevant instructions for the operation of the camera.

When the MAIN program (as depicted in FIGS. 9 and 10) is started, theinput conditions of the tele switch SWT, wide switch SWW, release switchSWR, photometric switch SWS and lock switch SWL are read and theirconditions are stored in a memory (step 1, which is also shown in FIG.34). When the main switch 30 is moved to the ZOOM position (or MACROposition) from the LOCK position, processing is transferred from theLOCK operation (described above and shown in FIG. 25) back to the MAINprogram that is shown in FIG. 34. At this time, charging flag FCHGST isset to 1, while charging flags FCHGRQ and FCHGDSP are set to 0 beforepausing for a period of 125 ms (step 50) before jumping back to step 3.At step 3, the input conditions of switches are re-read. The MAINprogram calls the zoom subroutines (which were discussed above) to movethe zoom lens to a location that matches the switch settings and thenreturns to the MAIN program, wherein the zoom subroutines are carriedout once more. This time, when the positions of the main switch and thezoom lens match, processing goes to step 47.

At step 47, the input condition of the photometric switch SWS stored inmemory and the input condition of photometric switch SWS that was readat step 3 are compared. Where there are no differences, processing goesto step 550, which checks whether flag FCHGST equals 1. As noted above,when processing is transferred to the MAIN program, the value 1 is setfor flag FCHGST. Therefore, processing goes to step 556 to determinewhether the strobe capacitor charging is completed. As the strobecapacitor has not yet been charged, processing is transferred to step556 to determine whether the strobe capacitor is being charged. If thestrobe capacitor is not being charged, processing goes to step 560 tostart charging the strobe capacitor (steps 560 and 562).

At step 554, the charging flag FCHGDSP is checked to determine if it isset to 1. When this flag has been set to 1, the read lamp indicator Rdwill blink (step 564) and processing is transferred to step 50 for the125 ms pause before jumping to step 3. When flag FCHGDSP is set to 0 instep 554, processing proceeds to step 50 without causing the red lampindicator Rd to blink. When there are no variations in the inputconditions of the tele switch SWT, wide switch SWW, release switch SWR,photometric switch SWS and lock switch SWL, the strobe capacitor ischarged in the loop 3 to 550, 556, 558, 556, 554, 50 and 3.

If the charging of the battery is not completed within 15 seconds, step566 will direct processing to step 568. This will stop the charging ofthe strobe capacitor and turn off the red lamp indicator Rd. Eventually,the routine will loop back to step S3.

When the charging of the strobe capacitor is completed, processingproceeds from step 556 to step 568. The charging of the strobe capacitoris stopped and the red lamp indicator Rd is turned OFF at step 568.Processing then continues to step 570, wherein flags FCHGST, FCHGRQ andFCHGDSO are each reset to 0. After the charging of the strobe capacitoris completed, the processing of steps 3 to 50 is repeatedly carried out.

At this time, if the shutter button is depressed and the photometricswitch SWS is ON, step 47 will judge that there is a charge in thephotometric switch SWS setting. Thus, processing goes to step 48 todetermine whether the photometric switch SWS is ON. If the photometricswitch SWS is OFF, processing goes back to step 550. When it is ON, theread lamp indicator Rd is turned off (step 572), the charging of thestrobe capacitor is stopped (step 574), and processing diverges to aseries of instructions that constitute a STROBE AUTOMATICEXPOSURE/AUTOMATIC FOCUS (SAEAF) operation.

In the SAEAF operation, illustrated in FIG. 35, distance finding dataDv, photometric data Bv and ISO data Sv are inputted (step 576). At step578, an exposure value Ev is calculated by adding the photometric dataBv and the ISO data Sv. Also, a FLASHMATIC (FM) operation is executedusing the exposure value Ev, distance finding data Dv and ISO data Sv.Thus, when it is necessary to use the strobe to obtain a properlyilluminated photograph, flag FFLASH will be set to 1, while when thestrobe is not required, flag FFLASH will be set to 0.

At step 580, a test is made to determine whether flag FLASH equals 1,meaning that the strobe is required. If the use of the strobe flash isnot necessary, processing diverges to a RELEASE PROCESSING operation, tobe discussed below. When step 580 determines that the strobe flash isnecessary, processing goes to step 582 to determine whether the strobecapacitor charging operation is completed. That is, a test is made todetermine whether the use of the strobe flash is possible. If it ispossible to use the strobe, processing diverges to the RELEASEPROCESSING operation, after the red lamp indicator Rd is turned ON (step584). The continuous illumination of the red lamp indicator Rd informsthe photographer that the strobe will flash when the shutter releasebutton is depressed. If it is not possible to fire the strobe, i.e., thestrobe capacitor is not fully charged, processing diverges to a seriesof instructions that constitute a CHARGE operation, after setting flagFCHGRQ to 1 (step 586). The CHARGE operation is illustrated in FIG. 36.

When processing diverges to the CHARGE operation, a charging timer isstarted at step 587 and charging is permitted at step 588. Thereafter,step 589 checks whether the strobe capacitor charging is completed. Whenit is completed, processing goes to step 590, wherein flag FCHGRQ is setto 0, the charging of the strobe capacitor is inhibited and the red lampindicator Rd is turned OFF (step 591). Processing then diverges back tothe SAEAF operation, which was previously described.

When the charging of the strobe capacitor is not completed, processinggoes to step 592 to determine whether the photometric switch SWS is ON.If the photometric switch SWS is OFF, processing goes to step 593 to setflag FCHGDSP to 1. The charging of the strobe capacitor is theninhibited and the red lamp indicator Rd is turned OFF (step 594).Processing then returns to the MAIN program listing of FIG. 34.

When processing returns to the MAIN program, it goes to step 564 toenable the blinking of the red lamp indicator Rd, because flag FCHGDSPwas set to 1 at step 593. Afterwards, processing returns to step S3,after the 125 ms wait in step 50. Until the strobe capacitor iscompletely charged, the red lamp indicator Rd will blink, whileprocessing goes through the loop comprising steps 3, 47, 550, 552, 556,558, 566, 554, 564, 50 and 3. After the strobe capacitor chargingoperation is completed, the red lamp indicator Rd is turned off (step568) and flags FCHGDSP, FCHGRQ and FCHGST are each set to 0 (step 570).Processing then goes to step 50.

If the shutter button is depressed and the photometric switch is set toON when the strobe flash is needed but not ready to flash, the strobecapacitor will start charging. The red lamp indicator Rd will also startto blink while the capacitor is being charged.

If the photometric switch SWS is ON at step 592 in the CHARGE operation,processing goes to step 595 to check whether the lock switch SWL is ON.If it is, processing goes to step 593 so as to inhibit the charging ofthe strobe capacitor and turn off the red lamp indicator Rd (step 594),before returning to the MAIN program. If the main switch 30 is not inthe LOCK position, processing goes to step 596, wherein a check is madeto determine if the charge time exceeds 15 seconds. When the charge timeexceeds 15 seconds, processing goes to step 597. If it does not exceed15 seconds, processing goes to step 598.

At step 598, processing is suspended for 125 ms before the red lampindicator Rd is activated to start blinking (step 599). When thephotometric switch SWS is ON (meaning that a photographer intends totake a photograph), the red lamp indicator Rd blinks to inform thephotographer that the strobe capacitor is being charged.

When the photometric switch SWS is set to OFF, processing is routedthrough steps 592, 593 and 594. In other words, the strobe capacitor isfully charged and the red lamp indicator Rd is turned OFF. Processingthen diverges back to the MAIN program.

As long as the photometric switch SWS is ON, a program loop occursbetween steps 589 and 599, so as to charge the strobe capacitor for amaximum of 15 seconds, or until the charging operation is complete,whichever comes first. This means that the strobe capacitor is chargedvia the instructions of the CHARGE operation while the shutter button isbeing depressed. On the other hand, when the shutter button is released,the charging of the strobe capacitor is carried out in response to theinstructions of the MAIN program.

If the strobe capacitor charging is not completed within 15 seconds atstep 596 of the CHARGE operation, processing goes to step 597 to setflag FCHGRQ to 0, turn off the red lamp indicator Rd and inhibit thecharging of the strobe capacitor (step 597A) before diverging back tothe MAIN program.

The RELEASE PROCESSING subroutine is illustrated in FIG. 37. In thissubroutine, a determination is made in step 610, as to whether therelease switch SWR is ON. When it is not ON, processing continues atstep 612, which determines whether the photometric switch SWS is ON. Ifthe photometric switch SWS is not ON, the red lamp indicator Rd isturned OFF at step 614 and processing returns to the MAIN program.However, if the photometric switch SWS is ON, processing goes to step616, wherein a determination is made as to whether the lock switch SWLis ON. If the lock switch is not ON, the subroutine loops back to step610. Therefore, if the release switch SWR is ON, the photometry switchSWS is ON and the lock switch SWL is OFF, the RELEASE PROCESSINGsubroutine performs a continuous loop between steps 610 and 616, untilone of these three conditions change. That is, the loop is terminated byeither setting the release switch SWR to OFF, setting the photometryswitch SWS to OFF, or by turning the lock switch SWL to ON.

When the photometry switch SWS is set to OFF, or the lock switch SWL isON, processing returns to the MAIN program.

When the release switch SWR is ON, the read lamp indicator Rd is turnedOFF (step 618) and the shutter is released (step 620). Strobe 22 is thenchecked (in step 622) to determine whether it is ready to flash. If thestrobe 22 is ready to flash (that is, Flag FLASH equals 1), processingproceeds to step 624, to set flags FCHGRQ to 1 and FCHGDSP to 0, so asto request charging of the battery for the next picture. In thissequence, because the photographer is not waiting to take a photo, flagFCHGDSP will be set to 0 and the red lamp indicator Rd will not light.Processing then goes to 626. If the strobe 22 is not ready to flash,processing goes from step 622 to step 626.

At step 626, it is determined if film is loaded in the camera. If filmis loaded, processing goes to step 628 to execute the FILM WIND-UPsubroutine to advance the film and then return to the MAIN program. Iffilm is not loaded, the FILM WIND-UP subroutine is skipped and controlreturns to the MAIN program.

The operation of the charging of the strobe according to the presentinvention provides the photographer with a clear indication as to thestatus of the charging process. This indication is shown to thephotographer only when he attempts to take a photograph. When thephotographer does not attempt to take a photograph, no charging statusindication is shown, even if the charging of the flash is actually underway.

The present invention has been described with regard to a specificnon-limiting preferred embodiment. It is to be understood that thepresent invention extends to all equivalents within the scope of thefollowing claims.

What is claimed is:
 1. An indicator unit for an electronicallycontrolled camera, comprising:(a) a first memory for storing a valuerepresenting a number of film frames which have been advanced by saidcamera; (b) a further memory for storing a valve representing a focallength of a movable lens associated with said camera; (c) means forselectively providing an indication on a specific portion of a displayarea of information corresponding to either said value representing saidnumber of advanced film frames or said value representing said focallength of said movable lens associated with said camera; (d) means forassigning a priority to providing an indication of informationcorresponding to said value representing said number of advanced filmframes by said means for providing an indication; (e) at least oneswitch that is actuatable to update said value representing said focallength of said movable lens associated with said camera in said furthermemory, said switch comprising a tele switch and a wide switch forenabling the movement of said lens associated with said camera; and (f)means for changing the indication provided by said means for providingan indication in response to the actuation of said switch, from saidvalue representing said number of advanced film frames to said valuerepresenting said focal length of said lens.
 2. The indicator unitaccording to claim 1, wherein said means for providing an indicationoperates in response to the actuation of said tele switch or said wideswitch.
 3. The indicator unit according to claim 1, wherein said switchwhich is actuatable to update said value representing said focal lengthof said lens comprises a light measuring switch.
 4. The indicator unitof claim 1, wherein said means for providing an indication ofinformation corresponding to said value representing said number ofadvanced film frames or said value representing said focal length ofsaid movable lens associated with said camera comprises a visualdisplay.
 5. The indicator unit according to claim 4, wherein said visualdisplay comprises respective display areas for indicating informationrelates to said film, information related to a picture-taking mode ofsaid camera and information relating to the status of a battery usedwith said camera.
 6. The indicator unit according to claim 5, whereinsaid display area for indicating information related to said filmcomprises a display area for requesting that said film be loaded intosaid camera, that the presence of said film has been sensed and thatsaid film is ready to be advanced to a predetermined position.
 7. Theindicator unit of claim 5, wherein said display area for indicatinginformation related to said film comprises a film-loading display areathat indicates when said film is being advanced to a predeterminedposition.
 8. The indicator unit according to claim 5, wherein saiddisplay area for indicating information related to said film comprisesdisplaying the number of exposed film frames which have been advanced bysaid camera.
 9. The indicator unit according to claim 5, wherein saiddisplay area for indicating information related to said film comprises adisplay for displaying said focal length of said lens.
 10. The indicatorunit according to claim 5, wherein said display area for indicatinginformation related to said picture-taking mode comprises a display forindicating a daylight synchro mode taking mode.
 11. The indicator unitaccording to claim 5, wherein said display area for indicating saidpicture-taking mode comprises a display for indicating a macro mode. 12.The indicator unit according to claim 1, wherein said switch comprisesan operation button array, said operation button array comprising (i) atwo-stage switch that operates as a photometry switch and as a shutterrelease switch; (ii) said tele switch; and (iii) said wide switch,wherein said two-stage switch, said tele switch, and said wide switchare actuatable by operating said operation button array, and whereinsaid means for changing the indication provided by said means forproviding an indication is responsive to the operation of said operationbutton array to actuate any of said two-stage switch, said tele switch,and said wide switch to display said focal length.
 13. The indicatorunit of claim 1, wherein said switch further comprises a film presenceswitch, and wherein said means for changing the indication provided bysaid means for providing an indication is responsive to the operation ofsaid film presence switch to display a request for loading a film intosaid camera.
 14. The indicator unit according to claim 1, wherein saidswitch further comprises a film advancement switch, and wherein saidmeans for changing the indication provided by said means for providingan indication is responsive to the operation of said film advancementswitch to display an indication that said film is being advanced.
 15. Anindicator unit for a camera, comprising:(a) a specific display area forindicating any of a plurality of items of camera-related information,said plurality of camera-related items including at least a valuerepresenting a number of film frames which have been advanced by saidcamera and a value representing a focal length of a movable lensassociated with said camera; and (b) means for controlling which of saidplurality of items of information is indicated by on said specificdisplay area, said controlling means comprising:(i) means for assigningan indication priority to at least one predetermined item of informationof said plurality of items of camera-related information, for enablingan indication of said at least one predetermined item of information onsaid specific display area under predetermined conditions; and (ii)means for overriding said means for assigning an indication priority,for enabling an indication of at least one predetermined other item ofcamera-related information on said specific display area underpredetermined conditions by operating a switch that enables a movementof said movable lens.
 16. The indicator unit according to claim 15,wherein said one predetermined item of information comprises said valuerepresenting the number of film frames which have been advanced by saidcamera.
 17. The indicator unit according to claim 16, wherein said atleast one predetermined other item of camera-related informationcomprises said focal length information of said movable lens.
 18. Anindicator unit for an electronically controlled camera, comprising:meansfor obtaining a value representing a number of film frames which havebeen advanced by said camera; means for obtaining a value representing afocal length of a movable lens associated with said camera; means forselectively providing an indication on a specific display area ofinformation corresponding to either said value representing said numberof advanced film frames or said value representing said focal length ofsaid movable lens associated with said camera; means for assigning apriority to provide an indication of information corresponding to saidvalue representing said number of advanced film frames by said means forproviding an indication; at least one switch that is actuatable toupdate said value representing said focal length of said movable lens,comprising:an operation button array having a two-stage switch thatoperates as a photometry switch and as a shutter release switch; a teleswitch for moving said lens towards a tele end; and a wide switch formoving said lens towards a wide end, wherein said two-stage switch, saidtele switch, and said wide switch are actuatable by operating saidoperation button array; and means for changing the indication providedon said specific display area, in response to the actuation of said atleast one switch, from said value representing said number of advancedfilm frames to said value representing said focal length of said lens.19. The indicator unit of claim 18, wherein said value representing anumber of film frames which have been advanced by said camera is storedin a first memory.
 20. The indicator unit of claim 18, wherein saidvalue representing a focal length of a movable lens associated with saidcamera is stored in a further memory.
 21. An indicator unit for anelectronically controlled camera, comprising:means for obtaining a valuerepresenting a number of film frames which have been advanced by saidcamera; means for obtaining a value representing a focal length of amovable lens associated with said camera; means for selectivelydisplaying either said value representing said number of advanced filmframes or said value representing said focal length of said lens on aspecific display area; means for assigning a priority for displaying onsaid specific display area either said value representing said number ofadvanced film frames or said value representing said focal length ofsaid lens; means for updating said value representing said focal lengthof said movable lens associated with said camera and said valuerepresenting said advanced film frames; and means for changing saidspecific display area to indicate said priority value in response tosaid updating means.
 22. The indicator unit of claim 21, wherein saidupdating means comprises a tele switch and a wide switch that operate tomove said lens associated with said camera.
 23. The indicator unit ofclaim 21, wherein said updating means comprises an operation buttonarray.
 24. The indicator unit of claim 23, wherein said operation buttonarray comprises:a tele switch for moving said lens towards a tele end; awide switch for moving said lens towards a wide end; and a two-stageswitch that operates as a photometry switch when said two-stage switchis depressed half-way and as a shutter release switch when saidtwo-stage switch is fully depressed.
 25. The indicator unit of claim 21,wherein said priority assigning means assigns said priority to saidvalue representing said number of advanced film frames.
 26. Theindicator unit of claim 21, wherein said priority assigning meansassigns said priority to said value representing said focal length ofsaid lens.
 27. The indicator unit of claim 26, wherein said updatingmeans comprises an operation button array that includes a tele switchfor moving said lens towards a tele end, a wide switch for moving saidlens towards a wide end and a two-stage switch that operates as aphotometry switch when said two-stage switch is depressed half-way andas a shutter release switch when said two-stage switch is fullydepressed.
 28. The indicator unit of claim 26, wherein updating meanscomprises a tele switch and a wide switch for enabling the movement ofsaid lens associated with said camera.
 29. The indicator unit of claim1, wherein said value representing said focal length of said movablelens is indicated upon the actuation of aid tele switch or said wideswitch.
 30. The indicator unit of claim 29, wherein said valuerepresenting said number of advanced film frames is re-indicated apredetermined period of time after said value representing said focallength of said movable lens is displayed.
 31. The indicator unit ofclaim 4, wherein said value representing said focal length of saidmovable lens is indicated on said visual display upon the actuation ofsaid tele switch or said wide switch.
 32. The indicator unit of claim15, wherein said overriding means comprises a light measuring switch.33. The indicator unit of claim 15, wherein said overriding meanscomprises a tele switch or a wide switch.
 34. The indicator unit ofclaim 15, wherein said priority indication is re-indicated apredetermined period of time after said at least one predetermined otheritem of camera-related information is indicated.
 35. The indicator unitof claim 18, further comprising means for re-indicating said valuerepresenting said number of advanced film frames after said indicationmeans has been switched to indicate said value representing said focallength of said lens.
 36. The indicator unit of claim 35, wherein saidreindicating means operates to permit the indication of said valuerepresenting said focal length of said lens for only a predeterminedperiod of time.
 37. An indicator unit for an electronically controlledcamera, comprising:means for providing an indication on a specificdisplay area of information corresponding to a value representing anumber of advanced film frames; means for providing an indication onsaid specific display area of information corresponding to a valuerepresenting a focal length of a movable lens associated with saidcamera; means for assigning a priority indication on said specificdisplay area to said information corresponding to said valuerepresenting said number of advanced film frames; and means for changingthe indication on said specific display area from said valuerepresenting said number of advanced film frames to said valuerepresenting said focal length of said movable lens in response to anactuation of a switch for driving said movable lens, said switchoperating to vary a focal length of said movable lens.
 38. The indicatorunit of claim 37, wherein said value representing said number ofadvanced film frames is stored in a first memory.
 39. The indicator unitof claim 37, wherein said value representing said focal length of amovable lens is stored in a further memory.
 40. The indicator unit ofclaim 37, wherein said switch comprises a tele switch and a wide switchfor controlling the driving of said movable lens between a wide end anda telephoto end.
 41. The indicator unit of claim 40, wherein said valuerepresenting said focal length of said movable lens is updated upon theactuation of either said tele switch or said wide switch.
 42. Theindicator unit of claim 37, wherein a different portion of said displayarea indicates further information related to a film used in saidcamera, information relating to the status of a battery used with saidcamera and information relating to a picture-taking mode of said camera.43. The indicator unit of claim 37, further comprising means forre-indicating said priority indication after the occurrence of aspecific event.
 44. The indicator unit of claim 43, wherein saidspecific event comprises the passage of a predetermined period of time.45. The indicator unit of claim 43, wherein said specific eventcomprises the actuation of a shutter in said camera.